Grazing
Handbook
A Guide for Resource Managers
in Coastal California
Sotoyome Resource Conservation District
PO Box 11526, Santa Rosa, CA 95406, Phone (707) 569-1448, Fax (707) 569-0434
Funding Provided by the State Coastal Conservancy
Production of this Handbook was made possible by a grant from the
State Coastal Conservancy
Administration provided by the Sotoyome Resource Conservation District
Technical Advisory Committee:
James Bartolome, Ph.D., Professor, Division of Ecosystem Sciences,
University of California, Berkeley
Gene Cooley, Botanist, Central Coast Region, California Department of Fish and Game
Jeffrey Creque, Ph.D., Agricultural Ecologist
Morgan Doran, Livestock and Natural Resources Advisor,
University of California Cooperative Extension, Solano, Yolo, and Napa Counties
Joyce Doughty, Sonoma-Marin Cattlemen and Sonoma-Marin Cattlewomen
Rich Gibson, Supervising Ranger, Marin County Dept. of Parks and Open Space
Grey Hayes, Ph.D., Coordinator, Coastal Training Program, Elkhorn Slough Foundation
Stephanie Larson, Livestock and Range Management Advisor,
University of California Cooperative Extension, Sonoma and Marin Counties
David Lewis, Watershed Management Advisor, University of California Cooperative Extension,
Sonoma, Marin, and Mendocino Counties
Garry Mahrt, Livestock Producer
Kathleen Marsh, Stewardship Planner, Sonoma County Agricultural Preservation
and Open Space District
Mischon Martin, Resource Ecologist, Marin County Department of Parks and Open Space
Lex McCorvey, Executive Director, Sonoma County Farm Bureau
Tony Nelson, Stewardship Coordinator, Marin Agricultural Land Trust
Charlette Epifanio, District Conservationist, Natural Resource Conservation Service,
Petaluma Field Office
Special Thanks to:
James Bartolome, Ph.D., for answering many questions and providing extensive technical information
Jeffrey Creque, Ph.D. for careful reading, many thoughtful comments, and providing
much of the information on riparian grazing
Larry Ford, Ph.D. for encouragement
Caitlin Bean for providing information on monitoring, birds and other wildlife
CONCEPT AND Writing : Lisa Bush
Editing : Elisabeth Ptak • Design : Lisa Krieshok
Table of Contents
B­ackground.................................................................................... 1
Geographical Context..................................................................... 1
Socio-economic Considerations ..................................................... 1
To Graze or Not to Graze: That is the Question............................. 2
Why is Grassland Management Important?................................... 3
Other Grassland Management Options.......................................... 5
Mowing....................................................................................... 5
Burning....................................................................................... 5
Understanding Grazing Basics ..................................................... 7
Impacts of grazers............................................................................ 7
Herbivory and Defoliation........................................................... 7
Trampling................................................................................... 8
Nutrients..................................................................................... 8
Kind and Class of Animal .............................................................. 9
Selecting Type of Livestock............................................................ 9
Foraging Differences..................................................................... 9
Tule Elk and Other Native Species.............................................. 10
Grazing Intensity.......................................................................... 10
Stocking Rate and Grazing Capacity............................................ 11
USDA Soil Survey Range Site Values......................................... 12
Direct Measurement................................................................... 12
Known Stocking Rates............................................................... 12
Scorecard Estimates.................................................................... 13
Grazing Periods and Grazing Systems.......................................... 13
Grazing Season.............................................................................. 13
Grazing as a Management Tool................................................... 15
Beneficial Uses of Grazing............................................................ 15
Fire Hazard Management......................................................... 15
Weed Management..................................................................... 16
Yellow star-thistle.............................................................. 17
Medusahead...................................................................... 17
Grazing Responses of Select Species.............................................. 18
Myrtle’s Silverspot Butterfly.............................................. 18
California Red-legged Frog............................................... 19
California Tiger Salamander............................................. 19
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Disadvantages of Grazing as a Management Tool......................... 20
Undesirable Vegetation Changes.................................................. 20
Erosion and Water Quality Impacts ........................................... 20
Negative Impacts to Wildlife . .................................................... 21
Recreational User Conflicts......................................................... 21
Planning a Grazing Program....................................................... 23
Adapting a Grazing Plan............................................................... 23
Setting Goals and Objectives ....................................................... 24
What are Goals and Objectives?................................................... 26
Contents of a Grazing Plan........................................................... 26
Who Can Help Develop a Grazing Plan?..................................... 27
Certified Rangeland Managers................................................... 27
Scientists and Academics............................................................. 28
Livestock Producers.................................................................... 28
Implementing a Grazing Program.............................................. 29
Infrastructure................................................................................. 29
Fencing...................................................................................... 29
Water......................................................................................... 30
Corrals and Chutes..................................................................... 31
Roads and Access........................................................................ 31
Barns......................................................................................... 31
Fostering the Landowner/Livestock Producer Relationship ........ 32
Developing a Grazing Agreement................................................. 32
Grazing Fees.................................................................................. 33
Payment per AUM..................................................................... 33
Payment per Acre....................................................................... 34
Exchange of In-kind Services in Lieu of Grazing Fees................. 34
Welfare Exemptions for Nonprofit Landowners........................... 35
No Gifts of Public Funds............................................................ 35
Fee-for-Service-Grazing............................................................ 35
How to Determine the Value of Grazing Fees.............................. 36
Role of Resource Conservation Districts . .................................... 37
Monitoring Grazing Use.............................................................. 39
What is Monitoring?..................................................................... 39
Why is Monitoring Important?..................................................... 39
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Monitoring Approaches................................................................ 39
Compliance Versus Effectiveness Monitoring............................... 39
Conducting Compliance Monitoring........................................... 40
Conducting Effectiveness Monitoring.......................................... 42
Common Types of Grazing Monitoring – RDM, Stubble
Height, and Percent Utilization............................................... 43
Minimal Monitoring Approaches................................................. 46
Photographic Monitoring............................................................ 46
Monitoring Riparian Grazing....................................................... 47
Select Habitat Types.................................................................... 49
Vernal Pool Grasslands.................................................................. 49
Coast Range Grasslands................................................................ 50
Management for Native Perennial Grasses.................................. 50
Riparian Systems........................................................................... 51
Riparian Grazing Management..................................................... 53
Exclusionary Fencing................................................................. 53
Riparian Pastures...................................................................... 54
Conclusion................................................................................... 57
Appendix Related Organizations and Sources of Information...... 59
Notes .......................................................................................... 61
Glossary........................................................................................ 65
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G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Background
This handbook is for public agency
personnel and private landowners who
may be interested in exploring the use of
livestock grazing to further their resource
management goals. It has been prepared for
smaller agencies and private landowning
organizations that do not have grazing
specialists on staff. We hope that the
information contained in this handbook will
broaden the understanding of the potential
applications of livestock grazing in various
grassland vegetation types and will help guide
decision-making about grazing programs.
While livestock grazing may not be a
management tool that all grassland owners or
managers will use, better understanding and access
to information about grazing will help landowners
and managers make informed decisions.
Geographical Context
This handbook addresses grazing
management on three important rangeland
types within the Sotoyome Resource
Conservation District (SRCD). These include
coastal grasslands, vernal pool grasslands,
and riparian areas. However, most of the
information contained in this handbook is
widely applicable to similar areas elsewhere in
coastal central California and beyond.
Socio-economic Considerations
Protecting the unspoiled parts of California is important to both residents and
visitors. Much of the character of rural areas comes from working landscapes.
Historically, this was based largely on an agricultural way of life where residents
made their livings from the land. Despite the fact that the economics of farming
and ranching no longer make that possible for many people, ongoing integration
of ranching in rural communities still plays a very strong role in preserving their
identities. Without ranching, private open lands may be subdivided where zoning
allows and converted to other uses, most likely increasing the residential density at
the expense of open views and the area’s agrarian lifestyle.
As with any business that depends on local infrastructure and services, the regional
survival of livestock ranching is threatened with each ranch that decreases in size
or goes out of business. Every livestock rancher depends on local services and
supplies including veterinary care, feed sales and delivery, farm and ranch supplies,
cattle buyers, and processing facilities. As land is taken out of ranching, all of
these services are incrementally affected. Eventually, some support businesses may
cease to operate, increasing the burden for ranchers who choose to keep ranching.
Because profit margins in the livestock business are slim, increased travel to access
services or supplies, or increased shipping costs to markets, can mean the end of
a family’s livestock business, and that in turn, affects others. Making appropriate
public and private conservation lands available to livestock producers encourages
continued productive economic use of those lands, to support communities while
providing potentially beneficial land management services to the public.
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
To Graze or Not to Graze:
That is the Question
The topic of livestock grazing on public
lands has for decades stirred emotionally
charged and often bitter controversy between
those in favor and those opposed. The “antigrazing” side has cited degradation of public
trust resources while the “pro-grazing” side has
held up the tradition of ranching in the West
as reason enough to continue this practice.
Beyond the emotional arguments,
however, is a complex web of scientific
information, ecosystem processes, and practical
issues related to grazing that must be carefully
considered before judging whether grazing is
“good” or “bad” or might be “right” or “wrong”
for any given situation. In most cases the
question is not black and white, but rather
a matter of weighing the expected effects of
grazing against the objectives for a particular
site. Grazing is sometimes referred to as a
“management tool,” so in many cases it should
be evaluated as such. “Will grazing help
achieve land management goals for this site?”
is a more appropriate question to consider
than “is grazing good or bad?”
Livestock grazing is a complex
phenomenon. It has many facets, from social
to ecological to economic. Each of these,
along with the impacts of the grazing animals
themselves – including trampling, defecating,
and urinating – must be carefully considered
in deciding whether or not grazing may be
favorable or detrimental for a given site.
Beyond the question of “to graze or not to
graze,” there are a multitude of qualitative and
quantitative variables that must be considered.
Species of animal, stocking rate, season of use,
and length of grazing periods are just a few of
the things that affect the outcome of a grazing
program.
Some wilderness advocates and
preservationists point out that livestock
grazing is not a part of California’s native
ecosystems, and thus believe that it doesn’t
belong in parks and other public lands. While
it is true that modern day grazing by European
and Asian livestock breeds does not necessarily
replicate the impacts of large herds of native
ungulates that once roamed the state, the only
large grazing animals currently found in most
of California are domesticated livestock.
The grazing ecology of California’s
grasslands extends back millions of years into
the Tertiary Period. Present day relationships
between grassland plants and grazing animals
are strongly linked to these prehistoric
associations.1 There is strong evidence
that many of California’s present-day
genera of native perennial grasses
evolved over millions of years with
the extensive megafauna, large
animals that once populated
California. Although massive
megafauna extinctions occurred
near the time of the last ice age,
during the prior two million
years in the late Pleistocene
Epoch, elephant-like mastodon,
mammoth, camel, llama, bison, elk,
pronghorn, horses, and numerous
other large herbivores roamed over
what is now California.2 These animals,
which browsed on brush and trees and
grazed on herbaceous vegetation, impacted
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
the landscape through their feeding habits
as well as through trampling that resulted
from herding behavior. Over the10,000
years since the last ice age, the only large
grazers present in California have been
elk, which have now been extirpated
from most of the state.
Plant residue found in fossilized
teeth and dung links some presentday plants with prehistoric grazers and
demonstrates the importance of grazing,
browsing, and trampling by large ungulates
in late Pleistocene California. Contemporary
grass genera that have been found in fossil
remains include wheatgrass (Agropyron) and
oatgrass (Danthonia). Observing California
oatgrass (Danthonia californica) in the field
shows clearly its adaptation to close grazing.
It is a short-statured native bunchgrass often
found in areas that are compacted, such as
along human or cattle trails, and in areas
where other short grasses prevail. It can be
found in extensive closely-cropped patches,
unrecognizable unless closely examined.
California, as we know it, has been
shaped by human management practices
for thousands of years. Burning was
conducted repeatedly by California Indians
to improve hunting of game, improve grass
seed production, and for many other other
uses.3 Anderson4 documents that “…land
management systems have been in place here
for at least twelve thousand years – ample
time to affect the evolutionary course of
plant species and plant communities. These
systems extend beyond the manipulation
of plant populations for food. Traditional
management systems have influenced the size,
extent, pattern, structure, and composition
of the flora and fauna within a multitude
of vegetation types throughout the state.
When the first Europeans visited California,
therefore, they did not find a pristine
wilderness but rather a carefully tended
garden that was the result of thousands of
years of selective harvesting, tilling, burning,
pruning, sowing, weeding, and transplanting.”
Many questions about the preEuropean condition and composition of
What are Rangelands?
Rangelands include grasslands, savannas,
and shrublands. When grazed by livestock,
these lands are called range. The unifying
characteristic of rangelands is that primary
productivity per hectare is typically lower
than croplands or forest lands.5 Rangelands
provide essential biological, scenic, economic,
and recreational values locally and
throughout the world. They are threatened
in many areas by development, conversion
to other intensive land uses, and alteration of
management regimes.
California’s landscapes and flora will always
remain unanswered. So, we must consider,
given the highly altered ecosystem that we
live in today, if grazing can play a constructive
role in preserving landscape patterns, native
plants and animals, managing fire fuels, or
otherwise help achieve resource management
goals.
Why is Grassland Management
Important?
Grasslands cover roughly nine percent
of California6 and support about 25% of the
State’s sensitive plant species.7 Grasslands
cover 22 to 23 percent of Sonoma County,8
and are threatened in many areas by
development, conversion to other intensive
land uses, and alteration of management
regimes. Within the SRCD, the vernal pool
grasslands of the Santa Rosa Plain exemplify
this threat. Many of these subtle depressions
in the earth that seasonally fill with water have
been lost or are threatened due to various types
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
of development, mismanagement, or simple
neglect. Management actions such as removing
livestock grazing from vernal pool grasslands
without providing alternative methods for
management of exotic annual grasses have
likely contributed to the decline of numerous
Santa Rosa Plain vernal pools.
California’s grasslands are dynamic
ecosystems that respond to seasonal changes in
our Mediterranean climate. Generally, annual
grasses and forbs, many of which are nonnative, germinate with the first fall rains, and
grow slowly through the cool winter. Perennial
species begin their growth at this time, after
surviving the dry summer in a dormant state.
In spring, with warmer temperatures and
adequate moisture, grassland plants grow
rapidly, with biomass production peaking
from late April to late May in most of the
SRCD. In drier parts of the state, growth can
end earlier; along the coast, green growth can
continue well into June or July. By mid- to late
spring, the biomass in ungrazed or very lightly
grazed grasslands can be so tall and dense
that small-statured species cannot get enough
sunlight or moisture to properly develop and
are essentially smothered. In late spring and
early summer, standing vegetation dries and
begins to decompose. Some species decompose
fairly quickly while others are more resistant,
remaining intact as dried straw-like thatch.
Thatch from species that are especially high
in silica, such as the exotic weed medusahead
(Taeniatherum caput-medusae) can pile up year
after year, so that the ground is covered in a
dense layer of dried plant material, preventing
sunlight penetration and germination and
growth of species that are poorly adapted
to these conditions. Disturbance or removal
of this biomass is essential for germination
and growth of some native species including
popcornflowers (Plagiobothrys spp.), clovers
(Trifolium spp.), owl’s-clovers (Castilleja spp.),
cream cups (Platystemon californicus), red maids
(Calandrinia ciliata), water chickweed (Montia
fontana), and many vernal pool forbs such as
downingia (Downingia spp.).9 Unmanaged
biomass can also adversely affect habitat for
certain animal species. For example, shore
birds are less likely to occupy grassland habitat
where standing biomass is over six inches tall.10
In grasslands that aren’t grazed or
otherwise managed to keep them open,
especially where they abut or intergrade
with shrublands, shrub invasion can convert
grasslands to coastal scrub. As well as
increasing fire hazards, this conversion results
in loss of coastal grasslands and thus, loss of
the species that occupy them. As noted by
Ford and Hayes,11 Northern Coastal Scrub,
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
a shrubland type, and Coastal Prairie, a
grassland type, are both increasingly rare
and endangered. Remaining areas of
Northern Coastal Scrub mature
to dense tall stands and often
encroach into coastal prairie and
annual grassland after termination
of periodic disturbances, such as fire
and grazing, which prevented such
encroachment. Cessation of periodic
burning and livestock grazing has
occurred where sprawl has fragmented the
landscape, and where changed ownerships
or cultural values now favor preservation with
little or no deliberate vegetation management.
As a result, remnant patches of Northern
Coastal Scrub are expanding in unmanaged
areas at the wildland-urban interface.12
Coyote brush is typically the first invader, and
may eventually become the sole community
member of such stands until other member
species can establish themselves.13
Other Grassland Management Options
Controlling brush encroachment and
preserving open grassland habitat requires
the mimicking or substitution of disturbance
processes that maintained open grasslands in
the past. In many cases, available management
options have been neither feasible nor
acceptable to the public or management
agencies. Meanwhile fire hazards, reduced
habitat, and reduced aesthetic values are
increasing problems.
Grazing is not the only method available
for managing grasslands, but frequently,
especially on a large scale, it can be the most
economical, reliable, and practical. Mowing
and prescribed burning are other grassland
management tools that have been used
successfully and may be preferred treatments
where animal use is impractical or where
objectives warrant.
However, while similar to grazing in
some ways, the effects of these treatments
are distinct from those of grazing. All
grassland management methods have unique
benefits and limitations, and the tool chosen
will depend on many factors including the
objectives for the site, current vegetation
composition, and funding availability. In many
cases, with careful planning and monitoring,
two or more of these treatments can be used in
conjunction to great effect.
Mowing
Mowing can be used on level-to-gently
rolling sites where the soil surface is fairly
even. On very small areas where livestock
management is not practical, mowing may be
the best way of managing grassland biomass.
However, it is a fairly labor intensive method
and must be repeated throughout the year for
consistent management of grassland canopy
height. Because mowing does not usually
involve removal of biomass from the site, it
often fails to address the problem of thatch
accumulation.
Prescribed Burning
As with grazing, some of the primary
effects of fire are mulch removal, increased
light and water penetration to the soil, nutrient
cycling, and control of grassland weeds. Fire
has been used effectively in establishing and
managing native grasses. Burns conducted
at the Jepson Prairie in Solano County, for
example, doubled average native species
richness and increased frequencies of several
uncommon native plant species while greatly
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
reducing the cover of medusahead.14 However,
there are some important distinctions between
grazing and burning, and factors such as
timing, intensity, and frequency of burns
must be carefully considered for each site and
will vary depending on objectives and site
characteristics.
Prescribed burning carries with it greater
liability than grazing, and acquiring permits
to burn is increasingly difficult because of
air quality concerns. While less expensive
than some other management tools, fire is
more costly than grazing. In many cases, so
much biomass has accumulated due to years
of excluding fire and grazing, that burning is
simply too hazardous to be easily initiated.
Appropriate burn prescriptions and good
relationships with fire agencies can sometimes
alleviate these issues, but grazing will likely
continue to be the more-favored tool for
managing extensive grasslands.
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Understanding Grazing Basics
Impacts of Grazers
Grazing animals affect plant
communities in several interrelated ways.15
They defoliate plants, remove and/or
redistribute nutrients, and cause mechanical
impacts on soil and plants through trampling.
Each of these affects is complex and may have
desirable or undesirable consequences for
individual species, plant guilds, or grassland
ecosystems. Keeping in mind the potential
impacts of these three primary influences
should help managers predict how grazing
might impact a site and its resources.
Herbivory and Defoliation
Herbivores are animals that feed on
plants; to defoliate means to remove leaves or
“foliage” from a plant. Aside from browsing
and grazing ungulates, other animals such as
insects and rodents and other natural processes
such as fire and hail can defoliate plants.
Herbicides, some of which are referred to as
“defoliants,” and mechanical methods such as
mowing and pruning also cause defoliation.
Defoliation affects the entire plant. Reduction
in leaf area of an individual plant reduces the
photosynthetic capacity of that plant which,
in turn, affects its roots, and can also affect its
reproductive capacity.
Some plants are more or less resistant to
grazing due to morphological characteristics.16
For example, plants with growing points
(meristematic tissue) that are low or close
to the ground tend to resist the effects of
herbivory more than tall plants with high
growing points.17 Grasses and forbs of different
species, life forms (i.e. annual versus perennial),
and growth habits (i.e. bunchgrasses versus
sod forming grasses) differ in their responses
to defoliation. Additionally, some plants have
mechanisms that reduce the chances of being
grazed, such as production of toxic compounds
or physical deterrents such as spines or
especially hairy foliage.
Selective herbivory influences the
structure and function of plant communities.
Grazing alters competitive interactions
among species by removing various amounts
of leaf area and establishing the potential for
differential growth rates.18 Species composition
is altered when a particular intensity,
frequency, and/or seasonality of grazing shifts
the competitive advantage from one group
of species to another. Grazing by livestock
or other herbivores affects different plant
communities in different ways.19 In general,
moister communities that evolved under
grazing, such as most grassland communities,
may be rather resistant to deterioration
caused by grazing. In fact, as discussed
above, many such communities depend
upon grazing or similar disturbance for their
persistence over time.
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Intensity, seasonality, frequency, and
duration of defoliation all affect plants and
their ability to resist and/or recover from
herbivory. In other words, how much leaf area
is removed, when is it removed, how often,
and for how long affect plant responses to
grazing. Responses to defoliation also depend
on: availability of meristematic tissue and
the developmental stage of new tiller buds;
carbon reserves and carbon balance; remaining
leaf area; light interception; time of year and
physiological growth stage; root area and
root growth factors; and the physical effects
of grazing animals on plants and soils.20
Recovery from grazing involves both the reestablishment of photosynthetic tissues and
the ability to retain a competitive position in
the plant community. Excessive defoliation
reduces both root system activity and leaf area
and may limit the plant’s capacity to compete
for and utilize soil moisture and nutrients.
This information can be applied to undesirable
plants in an effort to reduce their presence in a
plant community managed with grazing.
Trampling
While clipping or mowing can also be
used to remove above-ground plant biomass,
the effects are different from grazing which
also results in the pulling up and discarding of
unpalatable plant parts and, more significantly,
trampling. Trampling can be detrimental,
causing soil compaction and worsening some
types of erosion. It can also have beneficial
effects such as breaking up dead grass residue,
which aids in germination and growth of
small-statured wildflowers.
Trampling can help
mix manure and other
organic matter into
the soil surface, as
well as acting to plant
seed. Positive effects
of trampling include
changes in surface soil
bulk density that favor
desirable species over undesirable species. An
example is the tendency of poison hemlock
(Conium maculatum) to quickly dominate
sites under little or no grazing pressure, where
soils are light and very crumbly.21 Livestock
trampling on such sites can be used to rapidly
convert such sites to more desirable species
cover. The negative effects of trampling can be
minimized by controlling trampling intensity
in accordance with soil texture, soil moisture
and management objectives.
Nutrients
Grazing affects nutrient cycling in plant
communities in a variety of ways. Compounds
that can easily volatilize, such as readily
degradable carbon and some forms of nitrogen,
tend to be conserved in cattle feces, which
contributes to accelerated rates of humus
formation. As a particularly durable form of
soil organic matter, humus also increases both
the water- and nutrient-holding capacity
of soils. It increases biological activity and
other beneficial soil processes, improving soil
aeration and accelerating soil development.
By increasing soil organic matter, humus
also improvs water and nutrient-holding
capacity of soils. Grazing tends to increase
the proportion of clovers and other nitrogenfixing plants in the pea family by reducing
competition from taller grasses. These legumes
glean nitrogen from the air, which is fixed
in the soil by symbiotic rhizobia. Trampling
and the physical mixing of dead and decaying
plant material with manure, urine, and soil
hastens vegetation decomposition and makes
the nutrients bound in it available for use by
the soil and plant community. Of course, all of
these processes may be interrupted or reversed
if grazing is not properly managed to meet
these objectives.
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Kind and Class of Animal
Selecting Type of Livestock
Different species and classes of animals
have particular foraging habits, behaviors,
and other characteristics that may make one
preferable to another for meeting site-specific
management goals. Predator problems and site
topography are also important considerations.
Local availability of livestock types also may
restrict choices.
Different species of animals prefer
different topographic positions. Steepness of
slope significantly influences distribution of
cattle,22 while smaller animals, such as sheep
and goats, are more able to traverse steep
hillsides. Larger animals including cattle
and horses prefer to graze level-to-gently
rolling land. In areas with steep terrain, cattle
generally congregate on more level areas,
which can lead to heavy use of flat land
unless infrastructure or attractants are used to
improve distribution.
Foraging Differences
Grazing animals are divided into groups
based on their vegetation preferences and
primary foraging methods. These groups
include the grazers (cattle and horses),
which have a diet dominated by grasses and
grasslike plants, the browsers (goats), which
consume primarily shrubs and forbs, and the
intermediate feeders (sheep), which have no
particular preference for grasses, forbs, or
shrubs.23 Browsers commonly consume large
amounts of green grass during rapid growth
stages but avoid dry, mature grass and often
experience digestive upsets if forced to consume
too much mature grass.24
Body size and reticulo-rumen capacity,
anatomical differences in teeth, lips, and
mouth structure, grazing ability, and
differences in digestive systems account for
some of the differences in foraging behavior.
Mouth size directly affects the degree of
selectivity that is physically possible; ruminants
with small mouth parts such as goats, deer, and
pronghorn, in contrast to cattle, horses, and
elk, can more effectively utilize shrubs while
selecting against woody material.
In addition to physiological influences
on diet selection, animal behavior can strongly
affect what livestock choose to eat. Young
animals learn foraging behaviors from their
mothers and peers and can be taught to eat or
avoid certain plants.
Table 1.
Animal unit
equivalents25
Animal
Animal Monthly Forage
Kind andUnit
Consumption
ClassEquivalent
in Lbs.
Cow, dry
.92
727
Cow, with calf
1.00
790
Bull, mature
1.35
1,067
Cattle, one-year-old
.60
474
Cattle, two-year-old
.80
632
Horse, mature
1.25
988
Sheep, mature
.20
158
Lamb, one-year-old
.15
118
Goat, mature
.15
118
Kid, one-year-old
.10
79
Elk, mature
.60
474
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
Table 2. Generalized dietary and topographic site
preference characteristics by grazing animal species26
SpeciesDiet Preferences
Horse
Grazer: Mostly grasses,
minor forbs, and browse
Widely adapted to plains
Cattle
Grazer: Mostly grasses, some seasonal use of forbs
and browse
Prefers level to rolling land;
capable but often unwilling to
graze steep or rocky areas
Domestic sheep
Intermediate feeder: high use of forbs, but also use large volumes of
grass and browse
Better adapted to steep lands and rough terrain than cattle
Domestic goat
Browser to intermediate feeder: high forb use, but can utilize large
amounts of browse and grass;
highly versatile
Adapted to a wide variety of
terrain and vegetation types
Elk
Grazer to intermediate feeder: also considerable forbs and browse;
highly versatile
Prefer meadows, parks, bottoms,
and lower slopes; grazing often
concentrated
The amount of forage consumed is
affected by many factors, including breed and
age of animal. Although many other factors
can influence forage consumption, animal unit
equivalents (AUEs) can be useful in estimating
stocking rates and comparing forage demand
of different ages and species of animals.
Animal unit equivalents vary by source, actual
weight of animal, and individual animal.27
Table 1 gives AUEs for common domestic
livestock which can be calculated as follows:
3 mature bulls=4 animal units (3 x 1.35)
48 two-year-old cattle=38 animal units (48 x .8)
Tule Elk and Other Native Species
Tule elk (Cervus elaphus nannodes),
which are native grazers/intermediate feeders,
roamed California until the late 1880s. Tule
elk are classified as game animals and as such,
their management in California is governed
by the California Department of Fish and
10
Topographic Position Preferences
Game (CDFG). CDFG oversees several sites
where tule elk have been reintroduced, all of
which are extensive in size, providing adequate
acreage to support planned populations.
CDFG personnel have stated that no new
introductions of tule elk will be made in
California in areas where they cannot be
hunted, because without hunting, there is no
viable means of population control.28
Grazing Intensity
Intensity of use strongly affects a site’s
response to grazing. Grazing intensity is often
described as “light,” “moderate,” or “heavy,”
labels that are slightly more descriptive
than simply “grazed” or “ungrazed,” but still
reveal very little about a grazing regime. Two
variables – stocking rate and length of grazing
period(s) – are the principal controls that can
be prescribed to achieve the grazing intensity
desired for a site.
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Stocking Rate and Grazing Capacity
The terms stocking rate and grazing
capacity are interrelated. Grazing capacity
quantifies the amount of available forage for
grazing animals on a given site while stocking
rate is the number of animals grazing that
forage for a given period of time.
Initial stocking rates must be established
when grazing is newly introduced to a site.
Monitoring newly grazed sites over a several
year period should reveal whether or not
stocking rates are suitable.
Grazing capacity can be estimated and
stocking rates can be set based on site data
and simple mathematical formulas. However,
annual fluctuations in forage production
mean that setting and adjusting stocking rates
should be viewed as a process rather than an
exercise in determining a precise number of
animals that a site can carry. For example, the
grazing season generally begins in California
in the fall when annual grasses germinate and
start to grow in response to the first rains. By
late fall and winter, when cold weather sets
in, forage growth slows though feed intake
requirements of livestock do not. Warm
spring weather accelerates forage growth, with
peak production occurring in April and May.
During the summer, fall, and winter forage
deficits can occur; forage growth can exceed
forage demand in late spring. Supplemental
feeding of hay is often necessary during forage
deficits, especially to meet the nutritional
needs of pregnant or lactating livestock.
Forage production and grazing capacity also
vary between years, depending on amount
and distribution of rainfall and other climatic
factors.
In severe drought years or in years of
above-average forage production, stocking
rates may need to be adjusted downward or
upward during the grazing season to achieve
management objectives. This process can be
tricky, as it requires the livestock operator
to be flexible and to respond quickly to
unpredictable weather conditions that affect
forage production. A livestock producer who
must decrease stocking rates in response to
a spring drought may suffer financially. In
a good forage year, adding animals may be
difficult unless the operator has a large herd
with the ability to move animals from other
sites. Stocking rate can be adjusted down in
poor feed years by weaning calves or lambs
early, or culling more heavily than usual. In
good forage years, culling animals lightly or
retaining more replacement animals can be
used to increase stocking rates. A process for
adjusting stocking rates should be identified in
grazing agreements.
Grazing capacity can be estimated by
several different methods including: use of
forage production estimates for range sites
identified in the USDA Soil Surveys; direct
measurement methods that involve clipping
and weighing of vegetation; knowledge of
present or historical stocking rates on the site,
Grazing capacity is expressed in pounds
or tons of forage produced, often described
in animal unit months (AUMs). In intensively
managed rotational grazing systems, where
animals are moved frequently, animal unit
days (AUDs) may be used to describe forage
availability or consumption.
Stocking rate is expressed as animal units
(AUs) per time period.
Available forage is the forage produced
minus the amount of residual dry matter or
RDM desired.
……………………………………………
Grazing capacity and stocking rate
example: On a 100-acre site that produces
1,500 pounds per acre of available forage per
year, the total available forage production, or
grazing capacity, would be 1,500 lbs./acre x
100 acres = 150,000 lbs. of forage or 150
AUMs (150,000 /1,000 lbs./AUM).
Appropriate stocking rates for this site would
include 30 AUs for 5 months (30 x 5 = 150
AUMs) or 40 AUs for 3.75 months (40 x
3.75 = 150 AUMs).
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
11
or on a similar nearby site; and a scorecard
method based on climate zone, topography,
and tree canopy cover.29
USDA Soil Survey Range Site Values
The USDA Soil Surveys provide
estimates of forage production for range sites
and/or soil map units for “favorable,” “normal,”
and “less favorable” years. These values can be
used as rough guidelines.
Direct Measurement
Samples of current season’s biomass
should be taken from one-square-foot
quadrats located within representative areas
of the site, thoroughly dried, then weighed
with a gram scale. Weight in grams x 96 =
lbs./acre of forage. Depending how carefully
sampling is done, this can be a useful method,
although many samples may need to be taken
for accuracy, especially on sites where forage
production is highly variable.
Known Stocking Rates
Knowledge of current or historic
stocking rates and resultant site conditions
provide excellent estimates of forage
production. Depending on how well end-ofseason site conditions compare with desired
conditions, stocking rates can be adjusted to
increase or decrease the amount of grassland
biomass remaining at the end of the growing
season.
Mixed Species Grazing
Grazing by two or more species (separately or together) on the same pasture in a single growing
season is known as common use, dual use, or mixed species grazing. Where animal and economic
gain is the goal, or management objectives are advanced by grazing more than one species,
common use can be advantageous. The primary advantage to mixed species grazing is that forage
use can be more efficient. Two different species, cattle and sheep, for example, will differentially
graze, with the result that more diverse forage resources are utilized. As grazing use intensifies,
available forage decreases and the different animal species reduce their selectivity to maintain
adequate forage intake. This results in an increase in dietary overlap. Other advantages include
improved animal distribution, complementary food habits, diversification of income, and parasite
and disease management. Disadvantages include increased costs due to loss of feeds, reduced
efficiency within each species, and need for increased management.30
Common use may be an appropriate technique, but management goals for a specific site
may require a careful choice of animal species due to species-specific foraging habits or other
animal characteristics. Availability
of interested livestock producers
can also dictate the type of animals
available. Sheep ranching, for example,
has decreased dramatically on
California’s North Coast over the
past few decades, due primarily to
an increase in predation by coyotes
and, to a lesser extent, mountain
lions. Now, sheep ranchers must
use a combination of predator
deterrents including electric fencing,
guard animals, and where predation
is extreme, night-time housing for
animals.
12
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Scorecard Estimates
University of California researchers
developed a simple “scorecard” that can be
used to estimate grazing capacity on annualdominated rangelands based on desired RDM
levels and general site characteristics.31 This
method provides rough estimates based on
rainfall, canopy cover, and slope, and is most
applicable to large tracts of land dominated by
annual grasses and forbs.
Grazing Periods and Grazing Systems
A grazing period is the length of time
that animals occupy a specific land area, which
can range from less than one day to one year.
The term “grazing system” is sometimes used
to describe the way in which grazing and
nongrazing periods are arranged within the
maximum feasible grazing season (in coastal
central California, the grazing season is
year-round), either within or between years.
Grazing systems often have descriptive names
such as: continuous or yearlong grazing; shortduration grazing; deferred grazing; and restrotation grazing. Continuous grazing is the
simplest grazing system and is very common
in low-elevation California. Short-duration
grazing involves short periods (hours or
days) of grazing alternated with non-grazing
periods that are based upon plant growth
characteristics.
Grazing Season
Grazing can also occur seasonally within
a year. Different time periods for grazing
might be prescribed based on:
• type of livestock operation; for example, a
cow-calf beef operation requires pasture
all year to support the mother cows
• species targeted for enhancement or
control; for example, deferment of grazing
until after seed sets is sometimes used if
seed reproduction of a particular species
is critical; in other cases certain weed
species are grazed at critical times in their
development to weaken or kill them or
prevent reproduction
• saturated soils; grazing may need to be
deferred on sites with fragile soils.
• minimizing competition; late winter and
early spring grazing may be important for
reducing undesirable species competition
with native grasses32
• fire hazard control; where grass fires are
a concern, grazing should continue long
enough into the spring or summer to
adequately reduce standing fuels prior to
the fire season
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
13
14
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Grazing as a Management Tool
to manage the Italian ryegrass invasion and
Beyond the obvious benefits of livestock
butterfly numbers have rebounded. Properly
grazing such as food production, grazing can
managed grazing can enhance carbon
benefit individual plant and animal species, can
sequestration in rangeland
help manage fire hazards,
soils, helping to slow the rate
and, in the absence of
of increase in atmospheric
natural disturbance regimes,
CO2.33 On the other hand,
Grazing at
help maintain California’s
poorly managed grazing can
landscape structure. A land
Audubon Canyon Ranch’s
have undesirable effects, such
manager’s use of grazing
Bouverie Preserve
as unwanted changes in plant
can be viewed as application
“We want to favor native
species composition, negative
of a tool for keeping weed
annual
wildflowers
and
effects on wildlife species, and
or shrub invasion at bay,
perennial
grasses.
We’re
trying
acceleration or exacerbation of
enhancing wildflower
to reduce competition and
erosion.
displays, or maintaining a low
create some openings in the
grassland canopy height to
grass canopy. This will also
Beneficial Uses of Grazing
allow visibility, foraging, and
ultimately reduce thatch.”
movement of small mammals
Fire Hazard Management
such as voles and ground
—Daniel Gluesenkamp,Ph.D.,
The influence of livestock
squirrels.
Habitat Protection and
on
fire
hazard is two fold. First,
Restoration Specialist
As our highly altered
grazing at moderate levels has
environment becomes
been shown to change wildfire
more and more affected
behavior, by slowing its spread,
by development, industrial
shortening flame length, and
Sonoma
County
pollution, and global
reducing fire intensity, although
Agricultural Preservation
climate change, these
it does not significantly reduce
and Open Space District
impacts pose new threats to
the risk of fire ignition.34
native ecosystems, making
“One of the reasons that
Second, and most
livestock an increasingly
the District has grazing on
important
for long-term
important management tool.
its land is to support local
fire
safety,
especially
near
For example deposition of
agricultural producers – to
urbanized areas, grazing can
atmospheric nitrogen from
make
land
available
to
them.
prevent or minimize expansion
air pollution has dramatically
It’s
a
perfect
partnership.”
of shrublands which have
altered the chemistry of
much greater fuel loading
—Kathleen Marsh,
serpentine grassland soils at
Stewardship Planner
and pose greater fire hazard
Coyote Ridge near San Jose,
than grasslands. High-density
seriously threatening the
shrub cover can be seen
Bay checkerspot butterfly
throughout the San Francisco
(Euphydryas editha bayensis).
Bay Area where fires have
Excess nitrogen has resulted in an extensive
been
suppressed
for long periods and grazing
non-native grass invasion, primarily by
has
been
reduced
or removed. In particular,
Italian ryegrass (Lolium multiflorum), which
coyote
brush
(Baccharis
pilularis), occurs over
has eliminated many acres of dwarf plantain
large areas of ungrazed properties. McBride35
(Plantago erecta), one of the primary food
found that 51 years after grazing was removed
plants of the butterfly. Grazing is being used
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
15
from the Berkeley hills, coyote brush density
grasslands and oak woodlands, with a surface
had increased dramatically. Grasslands in the
biomass in the Baccharis shrublands more than
Berkeley hills that are grazed are relatively free 10 times greater than grasslands and more
than five times greater than oak woodlands. As
of coyote brush and other shrub species, while
well as greater fuel loading, results indicated
ungrazed grasslands in this area have been, or
the greatest average
are rapidly being,
flame length and
invaded by coyote
fire-line intensity
brush.
for shrublands
Biswell36
“Without modifications to our current and the lowest for
also described his
management strategies fire hazard
oak woodlands.
observations of
will likely continue to increase.”
The authors state
shrub invasion on
—Russell and McBride38
that these changes
a site in Berkeley
suggest “a general
that had been
increase in fire
burned frequently
hazard within the open spaces of the San
from the 1920s to the 1950s. When annual
Francisco Bay Area ” and that “the succession
burning was stopped in about 1960, he
from grasslands to Baccharis shrublands
observed that “…changes began to show in
indicates dramatic increase in fire hazard
the plant cover. Ripgut brome and coyote
for those areas” and “In the context of the
brush increased, and by 1984, no purple stipa
landscape matrix as a whole this increased
(Nassella pulchra) could be found.”
hazard indicates a greater possibility of fire
Although this observation relates to
being spread into adjacent forested areas and
cessation of a different disturbance regime,
residential communities.”
controlled burning, it illustrates the fact
that shrub invasion of coastal grasslands is
Weed Management
likely to occur in the absence of a regular
Livestock can be a useful tool in weed
disturbance regime.
management programs when the following
In a study of seven San Francisco Bay
conditions are met: 1) target plants are
Area open space sites, Russell and McBride37
acceptable as forage, 2) grazing can be
found that increases in shrub-dominated
timed to inflict damage at vulnerable periods
communities and decreases in grassland
in the weed’s life cycle, 3) water is available
since the 1940s and 1950s have increased the
for livestock; and 4) livestock are controlled
probability of high intensity fires. During this
to minimize damage to non-target species
time, fire has been generally excluded, and
and other ecosystem components. A land
grazing pressure has been reduced. Using aerial manager can manipulate various factors in a
photographs, their study measured the relative
grazing/weed management program: these
frequency of vegetation types including
include pasture or paddock size, location,
grassland, shrubland, and forest and woodland
and configuration; stocking rates; timing and
over time, and found that
frequency of grazing; and class of animal.39
in most cases, shrub
Use of portable electric fencing to facilitate
cover had increased short-duration, intensive grazing in small
significantly
paddocks is a component of most grazingover this period.
based weed management programs because
The heightened
animals must be forced to trample or eat plants
fire hazard is
that they would avoid given a choice in a larger
caused by the great
pasture.
increase of surface
Grazing has been shown to be effective
biomass in shrublands
in managing some species of noxious weeds
as compared with
that occur within the SRCD. Yellow star16
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
thistle (Centaurea solstichialis) and medusahead yellow star-thistle. No more than half of the
(Taeniatherum caput-medusae) have both been
grass should be removed.46
effectively managed through intensive grazing.
Medusahead. Grazing for control of
Yellow star-thistle. Properly timed
medusahead is experimental, but it has been
grazing can reduce yellow star-thistle seed
effective in research plots in Yolo County.47
production as demonstrated by controlled
Based on this research, essential components
experiments conducted over a three-year
of a grazing program for medusahead control
period with cattle, sheep, and goats at two
are: 1) critical timing; 2) high stocking density;
heavily infested sites in northern California
3) use of portable electric fencing; and 4)
by Thomsen et al.40 They used an intensive
a portable water supply. Research has been
grazing management approach, i.e., high
conducted with sheep, although goats and
stocking rates with short grazing periods that
cattle may also be effective.
were timed according to plant phenology and
Grazing should occur in late spring, as
regrowth responses. Grazing during rosette
soon
as
the flag leaf – the last leaf to emerge
stages (spring-grazed) led to an increase in
before the flower head – thickens and the stem
yellow star-thistle’s seed output and reduced
engorges. (The flag leaf emerges only days
competition from associated plants, giving
to a week before the flower head emerges, at
yellow star-thistle greater access to light,
which point the plants become completely
water, and nutrients. Intensive grazing using
unpalatable.) Heavy grazing at this time
large numbers of animals for short duration
ensures that the medusahead plants will not
timed to yellow star-thistle’s bolting, pre-spiny
flower and will not re-sprout, greatly decreasing
stages (late-May and June), was effective in
seed output. The window of opportunity for
decreasing yellow star-thistle flower head
41
this late-spring grazing is very short, which
densities, plant height, and canopy size.
means that careful monitoring and the ability
Timing of grazing is critical because viable
to move an adequate number of livestock onto
seed is produced by yellow star-thistle after
the property in a timely fashion is essential.
only a few percent of the flower heads have
42
If grazing occurs too
bloomed.
early, the plants will reHorses, which
sprout and if it occurs
can develop “chewing
too late, the livestock
“One common objective of livestock
mouth disease,” a fatal
will not graze the flower
nervous disorder, from
grazing on preserves is to reduce
heads. The timing of this
consumption of large
the amount of RDM. This allows
optimal phenological
quantities of yellow
sunlight to reach the soil surface
stage will vary depending
star-thistle, should
and stimulate germination of the
on weather conditions,
never be used for its
seeds of native species.”
43
but usually occurs in late
management, although
— J. W. Bartolome45
April.
it is an acceptable forage
for ruminants.44 Sheep,
The intensity of
goats, and cattle eat
late-spring grazing should
yellow star-thistle before
be heavy, which may
spines form on the plant. Goats will eat starresult in a higher proportion of bare ground
thistle even in the spiny stage. It is a nutritious
than would normally be considered acceptable.
plant, especially when in the rosette stage with
Grazing episodes may need to be followed with
crude protein ranging from 28% in this stage
fall seeding or other erosion control methods,
especially on slopes. Experimental stocking
down to 11% at the bud stage. Grazing should
densities for late-spring grazing have been on the
not be as intensive as for medusahead control
because remaining grass helps to shade out
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
17
order of 5 AUs per acre, or as needed to graze
herbage down to a height of about two inches.
Grazing Responses of Select Species
Scientists and practitioners have
documented the grazing responses of numerous
individual plant and animal species. On sites
where legally protected special-status species
are found, grazing is increasingly used to
enhance their habitat. Animals whose habitat
requirements can be promoted by grazing
include insects, amphibians, mammals, birds,
and reptiles. With its inherent complexity
across the landscape, grazing can promote
habitat heterogeneity by creating a matrix of
plant species with varying structure for a wide
variety of wildlife. For example, in some parts
of California, areas grazed to lower RDM
levels may be suitable for small mammals
such as kangaroo rats (Dipodomys spp.) that
prefer open habitats for ease of movement
and foraging. Other small mammals, such
as the locally occurring California meadow
mouse (Microtus caifornicus) prefer more
lightly grazed areas with substantial standing
vegetation that provides nesting sites and
protective cover. Similar patterns of use across
a range of grazing levels occur with birds.
Some ground nesters and birds that dart across
the ground, such as endangered
mountain plovers (Charadrius
montanus), prefer very open
uplands that may have been
grazed intensively while
the locally common
western meadowlark
(Sturnella neglecta) spends
more time in denser
grasslands. Other birds, such
towhees (Pipilo spp.), prefer to
forage and nest in relatively dense brush.
Various native wildflower species may
also respond well to grazing. To determine
whether or not grazing might benefit
individual species, it’s important to first
describe the various habitat elements that they
require, then analyze how and when livestock
could impact them, positively or negatively.
18
Carefully thought out, site-specific goals
and objectives for grazing should be used to
identify target RDM levels or other desired
habitat conditions.
Below are examples of locally represented
taxa that appear to benefit from appropriate
grazing regimes.
Myrtle’s Silverspot Butterfly (Speyeria
zerene myrtleae) is a federally-listed endangered
species that inhabits coastal dunes, coastal
prairie, and coastal scrub. Critical to its survival
is the larval host plant dog violet (Viola
adunca) and nectar plants for adults to feed on.
Nectar plants include a variety of native and
non-native species including the non-native
bull thistle (Cirsium vulgare). This butterfly
occurs locally at the Point Reyes National
Seashore and on private lands in Sonoma and
Marin Counties. Until 1990, when populations
on private lands were discovered, the Point
Reyes population was believed to be the only
one that was thriving. Despite the wide range
of potential habitat and the large area over
which the butterfly was observed at Point
Reyes, the butterfly population densities were
found to be relatively low.48 By comparison,
a similarly sized population was found on a
private site roughly one-tenth of the size of
the butterfly’s observed Point Reyes
territory. The private site, which
has been grazed commercially
for more than a hundred
years, apparently supports
a much greater density
of Myrtle’s silverspot
butterflies than the Point
Reyes sites.
Murphy and Launer49
concluded that the areas on
the private site found to have the highest
concentrations of adult Myrtle’s silverspot
butterflies, probably are also the areas likely to
support butterfly larvae, which are dependant
on higher concentrations of dog violet host
plants. Data collected in paired grazed and
ungrazed plots at three locations within PRNS
show dog violet to occur more frequently in
grazed plots.50
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
California Red-legged Frog (Rana
aurora draytonii), a federally-listed threatened
species, occurs throughout the SRCD and
other parts of California in grassland, oak
woodland, oak savanna, riparian scrub, and
riparian woodland.51 As documented in the
Recovery Plan for the
Red-legged Frog,52
in many cases
they co-exist
with managed
livestock grazing.
High numbers
are found in
grazed areas
including Point
Reyes National
Seashore, East Bay
Regional Parks, and private land holdings
where stock ponds and cattle are prevalent.
The Recovery Plan states, “In many of these
areas, California red-legged frogs may be
present only because livestock operators have
artificially created ponds for livestock water
where there were none before and therefore,
created frog habitats. In such ponded habitat,
grazing may help maintain habitat suitability
by keeping ponds clear where they might
otherwise fill in with cattails, bulrushes, and
other emergent vegetation.” The Recovery Plan
also points out that cattle may cause negative
impacts to California red-legged frogs by
crushing eggs and/or disturbing egg masses,
negatively affecting riparian habitat, marshes,
and ponds and can have other detrimental
effects.
Red legged-frogs reside in or near
streams, marshes, and stock ponds, preferring
pools or slow water with dense overhanging
vegetation. They attach their eggs to emergent
vegetation and use upland grassland habitats
and rodent burrow or woody litter refuges
up to one mile from breeding areas during
November to March (movements prior
to breeding) and July to October (post
metamorphic juvenile dispersal). During
periods of movement, the frogs are vulnerable
to trampling by livestock, but on the other
hand, excess upland grass height can hinder
movement during these times. Excessive
damage by livestock to emergent aquatic plants
or plants that provide breeding or sheltering
habitat at the water’s edge could have negative
effects. East Bay Municipal Utilities District53
classifies red-legged frogs as moderately
vulnerable to livestock impacts, citing such
negative effects as damage to emergent aquatic
and riparian vegetation. Since the Recovery
plan implies that livestock can help keep
emergent vegetation from becoming too dense,
allowing periodic livestock access to ponds
can be used to manage emergent vegetation
without overuse.
California Tiger Salamander
(Ambystoma californiense) inhabits grassland
and oak savanna with rodent burrows used for
summer retreats, and ponds used for breeding.
They emerge from their subterranean refuges
with the first rains and migrate to seasonal
wetlands such as
vernal pools,
stock ponds,
or slow streams
that hold water
through May.
Breeding occurs
from December to early February with larvae
transforming in water by late spring or early
summer. Juveniles disperse from breeding
sites in late spring to early summer. Very little
information is available regarding the effects
of livestock grazing on the salamander. Like
other small animals, they are vulnerable to
trampling during migration periods, and are
also sensitive to excess herbaceous vegetation
height54 which can hinder their movement
from November to March (adults) and
March to August (juveniles). Conditions that
could lead to premature drawdown of pools,
such as excessive spring evapotranspiration
from annual grasses, could degrade breeding
habitat. According to Huntsinger and
Ford55 the salamander requires access across
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open grasslands, thus insufficient grazing
and associated grass height and shrub
encroachment would reduce habitat quality.
Disadvantages of Grazing as a
Management Tool
While grazing can be beneficial for
some species and in some habitats when
appropriately prescribed, poorly managed
grazing or grazing of unsuitable sites can
cause serious environmental damage. As with
most management methods, even when well
managed, grazing carries some risks to natural
resources, wildlife, and occasionally to human
health and safety. With thoughtful planning,
serious grazing-related issues can be avoided.
Undesirable Vegetation Changes
As discussed throughout this Handbook,
grazing can strongly affect vegetation.
Stocking rates that are too high and
inappropriate seasons of use, especially over
long periods of time, can result in serious
negative consequences. Browsing of woody
plants by livestock can negatively affect
plant communities. For example, livestock
grazing when oaks are in leaf can damage
or kill seedlings and saplings unless they are
protected by livestock exclosures. Poorly timed
or heavy grazing in riparian areas can lead
to loss of woody riparian canopy, which can
degrade habitat for many wildlife species.
Repeated, prolonged heavy grazing can
exacerbate infestations of some weed species
that thrive in highly disturbed environments.
Purple star-thistle (Centaurea calcitrapa) and
20
woolly distaff thistle (Carthamnus lanatus)
are more prevalent in areas that are heavily
grazed or trampled. Livestock avoid grazing
these spiny plants but eat the forbs and grasses
around them, reducing competition with
thistle seedlings. Unfortunately, the same
conditions that encourage the germination and
growth of native forbs – reduction of annual
grass canopy height and density – can also
promote establishment of weed populations.
Erosion and Water Quality Impacts
Erosion and water quality impacts are
common concerns on grazed lands. Some types
of erosion can be exacerbated or accelerated
by livestock and can cause degradation of
upland soils and/or sedimentation of waterways.
Sediment, nutrients, and pathogenic organisms
can degrade water quality for fish, wildlife, and
human uses.
Sediment that is mobilized and reaches
stream channels can damage anadromous fish
habitat by filling in gravel beds, making them
unsuitable for spawning or smothering
developing fish eggs in the gravel.
Sediment can also fill in deep pools
that remain cool in the summer and
provide habitat for young fish.
Streambank erosion, which
can be caused or exacerbated by
livestock that have free access to
riparian areas, results in eroded soil
being deposited directly into affected
waterways. Upland erosional processes,
on the other hand, also move sediment but,
depending on specific geomorphic processes
and site conditions, this sediment may or may
not be transported into a stream.
Sheet and rill erosion commonly occur
on unpaved ranch roads, and can also occur
on bare ground in animal confinement areas.
This type of erosion is less likely to occur on
grazed pastures, unless grazing intensity is
excessive. Concentrated flows on hillslopes,
from activities such as road building, livestock
trailing, and gopher or other animal burrowing
can cause gully initiation. Minimizing animal
trailing that is parallel with slopes, and
maintaining adequate vegetation cover can
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
guard against concentrated runoff and, thus,
the chances of livestock-induced gullying.
Terracettes, or grazing terraces, are
geomorphic features that can be caused by
livestock trailing on steep hills. They can
increase infiltration into slopes, which can
increase the potential for landsliding if other
site conditions favor this type of hillslope
erosion. They may also serve as conduits for
concentrated flows of water, and may lead to
gully formation.
Nutrient and pathogen pollution of
surface waters from animal waste can result
from rangeland grazing, but most often occurs
when livestock are confined and animal wastes
are concentrated. Minimizing or preventing
livestock access to perennial streams and
avoiding excessive concentration of livestock
should minimize this possibility.
Ammonia from livestock wastes
can cause acute toxicity to aquatic species.
Pathogens are a less common but potentially
serious source of water quality degradation.
Since pathogens are transmitted through
animal wastes, the same conditions that
cause nutrient pollution can cause pathogen
pollution. Many of the pathogens that are
carried by livestock can cause illnesses in
humans and wildlife.
Pathogenic organisms include
bacteria, viruses, and cysts. More than 150
pathogenic organisms can be transmitted
through livestock waste. Some of the most
common include Giardia, Leptospira, Brucellas,
Salmonella, and Cryptosporidia. Pathogens
can also be carried by wildlife;
for example, the presence of
botulism in stagnant water
can devastate waterfowl
populations. Livestock
grazing in watersheds that
provide domestic water
for urban areas has raised
concerns about some cattleborne pathogens, especially
Cryptosporidium parvum. This pathogen poses a
danger to persons with compromised immune
systems. Generally, calves up to three or four
months of age shed more Cryptosporidia on a
per weight basis than older or heavier animals.56
Negative Impacts to Wildlife
Although grazing
can provide habitat
heterogeneity for
many bird species,
birds that nest in the
lower strata of riparian
vegetation, such as
yellow warbler (Dendroica
petechia), Wilson’s warbler
(Wilsonia pusilla), warbling
vireo (Vireo gilvus), and song
sparrow (Melospiza melodia); or
on the ground, such as dark-eyed
junco (Junco hyemalis), California quail
(Callipepla californica), and spotted towhee
(Pipilo maculatus) can be adversely affected by
grazing. Grazing in riparian areas during the
nesting season can destroy nests and expose
nests to predators through removal of cover.
The brown-headed cowbird (Molothrus ater),
which increases when cattle are present,
parasitizes the nests of other birds, laying her
eggs for other species to incubate. The young
cowbirds are often larger and more competitive
than other songbirds and have a serious impact
on other species’ reproductive success.57
Heavy grazing can also cause shifts in
rodent populations, affecting predatory birds
populations. As with plant species, impacts to
wildlife species should be carefully considered
in any grazing plan or program.
Recreational User Conflicts
Conflicts between
livestock and recreational
users can occur on public
lands that are grazed.
Although reports of injury
are rare, complaints about
livestock and potential liability
are cause for concern. The
few incidents of aggression by
cattle toward visitors at Point Reyes National
Seashore have occurred when unleashed dogs
have approached mother cows with young
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calves or when people have come between the
cow and her calf.58
Bulls can also be aggressive and can cause
serious injury. In most cases, bulls should
not be in areas with public access. On public
recreational land or private land that will
allow recreation or visitation, caution should
be used in determining what kind and class of
livestock will be on site. In some cases, it may
be best to have access closed on all or part of a
property during certain times of year, such as
22
calving season. Recreational users may regard
livestock as a nuisance due to their impacts on
trails, manure and flies, and perceptions about
damage to natural resources. Concerns such
as these may be best addressed through public
education, including signage.
For livestock producers, conflicts and
concerns caused by recreational users include
gates left open and aggression towards
livestock by unleashed dogs.
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Planning a Grazing Program
Planning for grazing is a process that can
culminate in a product – a grazing plan – but
it should begin even before land is acquired
by an agency or organization. For example,
certain physical improvements such as water
and truck and trailer access are necessary to
facilitate grazing on any given site. In the case
of partial acquisitions, when properties are
divided and sold in pieces, these important
improvements are sometimes retained by the
original owner or otherwise separated from
the acquired parcel. If establishing a grazing
program is later desired, it may be impossible
due to the absence of this infrastructure.
In the case of publicly-owned or private
conservation lands, having a written plan for
grazing is important because:
• many public agencies or private
land conservation organizations lack
expertise in grazing management, and
a professionally prepared grazing plans
provide essential information and
instruction
• by law in California, range management
planning on “forested landscapes” requires
a state license except when conducted
by an individual private landowner or on
federal land
• along with monitoring data, a plan
provides a record of management activities
against which the effects of grazing can
be evaluated; if land management goals
aren’t achieved after the grazing plan is
implemented, the original plan can be
modified
Adapting a Grazing Plan
Once a grazing plan has been written, it
should be reviewed periodically and updated
as new information becomes available or
management objectives change. Information
gathered through monitoring should be
used to evaluate goals and implementation
methods, and to modify the plan to
improve future results. This common sense
approach is the origin of the term “adaptive
management,” which was coined in the early
1970s. Adaptive management is the process
whereby management is initiated, evaluated,
and refined.59 The concept of “adaptive
management” complements the notion of
“Best Management Practices,” by explicitly
Why is Planning Important?
“Planning for grazing is important for the same
reasons that it’s important for anything else – it
gives direction. It also provides a strategy for
implementation and a basis for monitoring which
allows you to adapt your actions to continue
improving management.”
— Sheila Barry, Natural Resources and
Livestock Advisor, University of California
Cooperative Extension, Bay Area
“ You need to know that you’re working toward
your goals. With a grazing plan you know where
you’re heading and it allows you to move step-bystep in the right direction. It also helps you know if
you’ve achieved your goals.”
— Stephanie Larson, Livestock and Range
Management Advisor, University of California
Cooperative Extension, Sonoma and Marin Counties
“The District needs to show how they’re spending
taxpayer’s money and to have a plan for taking
care of the resources…and for grasslands, that’s
always going to include grazing. The land has
always been grazed – first by native ungulates,
then by livestock. Grazing enhances biodiversity
and keeps fire danger down.”
— Kathleen Marsh, Stewardship Planner,
Sonoma County Agricultural Preservation
and Open Space District
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recognizing that what is thought to be
“best” now may change as new information
about a site becomes available. It differs
and paves the way for a positive working
relationship among all the stakeholders.
The concerns of potential livestock
operators must be considered in setting
goals because without the cooperation of a
suitable implementation partner, even wellplanned grazing programs can fail. Ideally, the
landowner and livestock operator would share
common goals. However, these two parties
often have different fundamental reasons
for being involved with grazing. While land
managers may have ecological goals driving
their decision to have livestock grazing on a
site, the livestock operator’s primary goal is
from traditional management approaches by
usually economic. Potential lessees should be
recognizing and preparing for the uncertainty
included in the planning process along with
that underlies resource management decisions.
other stakeholders whenever possible to get
The formal adaptive management
their input and buy-in.
process, as shown in the following diagram,
With clear goals and objectives, many
consists of a six-step cycle that is a useful
of the possible affects of grazing can be
framework for grazing planning where the
individually evaluated in relation to desired
“design” step equates with preparation of a
outcomes. As the favorable effects of livestock
written plan. A less
grazing become
structured approach
more widely
is to continually
“Effective goals should be well defined with
recognized, some
fine-tune grazing
land managers
time frames and clear, measurable objectives.
plans as monitoring
are eager to try to
For a public agency, well-defined goals
reveals useful
accomplish many of
create accountability.”
information and/or
their goals through
— Sheila Barry, Natural Resources and
conditions change.
grazing. For example,
Livestock Advisor, University of California
Unfortunately,
fire fuel control,
Cooperative Extension, Bay Area
although adaptive
weed management,
management is held
enhancement of
up as an ideal management model and its use
grassland biodiversity, and improvement of
is sometimes required by regulatory agencies,
wildlife habitat all can be positively affected
the expense of detailed monitoring and
by livestock grazing. These may be reasonable
assessment mean that it is seldom put into use. goals for a grazing program but they must be
examined in detail and on a site-specific basis to
Setting Goals and Objectives
determine if they can be met through grazing.
Regardless of the planning model
There are many approaches to goal setting
used, setting goals and objectives is the most
but several rules always apply. Goals must be:
important step in developing a grazing plan.
• consistent with agency and/or land
Goals are the foundation upon which specific
management policies
prescriptions should be made within regulatory
• consistent with local, state, and federal
parameters. Goal setting is especially important
laws and regulations
when numerous entities (agencies or people)
• attainable
have a stake in management of a site. The
• measurable (through objectives)
process of setting goals and objectives helps
identify each stakeholder’s needs and desires
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Experience is the Best Teacher
A Lesson in Goal Setting
The Marin County Open Space District’s Mount Burdell Open Space Preserve provides a
scenic backdrop to the City of Novato and an important recreational site for hikers, joggers,
and equestrians. Its 1,560 acres of grassland and oak woodland also support many plant
and wildlife species, including several special-status species. Entities that have a stake in its
management include District staff, recreational users, nature lovers, adjacent residents, and,
because of its forage resources, the local ranching community. Additionally, fire management
agencies have an interest in vegetation management as it relates to fire hazard. The site has
been grazed by livestock for over a century, with a formal grazing program put in place in
1989, about 15 years after it was purchased by the District. Grazing use was initially retained
after the District’s acquisition to provide fire fuel management and because neighbors
wished to retain their views of the pastoral landscape.60
Initial grazing program goals were:
• to preserve and enhance the native plant and wildlife habitat for
the enjoyment and use of Marin County and regional residents
• to preserve the soil and water resources and productivity of the
Open Space
• to manage the fuel loads so as not to endanger the homes
adjoining the Open Space and
• to maintain the pastoral values associated with the important
dairy industry in Marin County
A grazing program has been operated on the site for 15 years based on these goals.
Complaints about grazing impacts from local residents and recognition that some of the
goals were not being met led the District to reevaluate its grazing program.
This reevaluation process identified potential incompatibilities between and within
these goals, and recommended that they be carefully evaluated and prioritized with
management directed at achieving one or more of the highest priority goals.
For example, goals addressing “fire fuel management” and “preserving soil and water
resources” may have inherent conflicts – while soil and water resources would be best
protected by lighter grazing for a shorter time period, fire fuel reduction would require a
more aggressive grazing program with less biomass retained at the end of the season.
Preserving and enhancing “the native plant and wildlife habitat” would require
identification of target species and their habitat requirements. Which native plants should
be favored and what are the most important wildlife species? Different guilds of plants
(i.e. grass versus forbs and annuals versus perennials) may react differently to a given
grazing regime. High levels of grassland biomass can hinder some wildlife species while
benefitting others.
Attempting to meet all of these goals would be a complicated task requiring establishment
of specific objectives. Clear, realistic management goals must be established and prioritized
before the existing grazing program can be evaluated to determine its effectiveness. The
District is in the process of evaluating and simplifying its goals, and making appropriate
adjustments to its grazing program.
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What are Goals and Objectives?
Contents of a Grazing Plan
Because goals, which represent a future
There is no single best way to write a
desired state or condition, are often general or
grazing plan, but there are certain elements
idealistic, they should be paired with specific
that should generally be addressed. These
and practical objectives. Goals are what you
include:
want to have accomplished while objectives set Site Description and Resource Inventories.
out how they will
These are sometimes
be accomplished.61
referred to as
Goals don’t have
“Existing Conditions”
“The most important thing is really being
to be lofty – they
and should
clear on your goals first, because everything
can be simple
contain text, maps
statements, such
comes out of that.”
(topographic and
as “maintain
—Bob Neale, Sonoma Land Trust
aerial photography),
the beauty of
Stewardship Director
and other graphics as
wildflower fields.”
needed to thoroughly
Goals should
document a site’s
be practical and clearly stated, avoiding jargon. physical properties and resources, including:
If “enhancing native biodiversity” is a goal,
• property boundaries
include an explanation of what this means.
• vegetation, including special-status species
Are there particular native species on site
and important forage and weed species
that might be favored by grazing? Are there
• wildlife, including special-status species
protected species that, by law, require special
• soils, as described and mapped in USDA
consideration?
Soil Surveys; soils information can help
Goal statements should begin with
predict forage production and erosion
an action verb like “increase,” “reduce,” or
potential that can be affected by grazing
“provide”.62 For example, 1) “to increase native
• topographic and hydrologic features
forb diversity,” 2) “to reduce cover of noxious
including wetlands and streams, especially
weeds,” or 3) “to provide a forage base for local
those that are fish bearing; for larger
ranchers” could all be goals.
properties, USGS quadrangle maps may
Complimentary objectives could be 1)
be adequate; more detailed information
“decrease annual grass biomass by 50% during
may be available in local watershed plans
March, April, and May, to reduce competition
or resource studies
with native forbs for sunlight and moisture,”
• information on other sensitive resources;
2) “intensively graze medusahead in spring as
archaeological sites or other cultural
soon as the flag leaf (the last leaf to emerge
resources that could be adversely affected
before the flower head) thickens and the stem
by grazing should be identified
engorges to reduce seed output,” and 3) “lease
• grazing infrastructure inventory and
the property to an established, local rancher by
condition, including water sources and
a specific date.”
livestock watering locations, roads,
Lastly, goals may need to be prioritized.
fencing, gates and vehicular access
Some goals may conflict with others and it
locations, corrals and loading chutes,
may be necessary to select one or more at the
and barns
expense of another.
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Land Use Information
• historic use records, Natural Resources
Conservation Service (NRCS)
conservation plans, and farming or
ranching records can reveal information
that helps explain current conditions; for
example, evidence of prior cultivation,
irrigation, or fertilization may explain
degraded populations of native plant
species
• current and planned future uses should
be identified in as much detail as possible,
especially on lands used for public
recreation; certain types of recreation may
be incompatible with grazing
Goals and Objectives
• general goals
• specific, measurable objectives
Grazing Recommendations/Prescriptions
• grazing capacity of site
• initial stocking rate and methods for
adjustment
• recommended kind and class of animal
• grazing units and pastures
• timing of grazing
• methods for animal distribution
• infrastructure improvements and
maintenance
• grazing effects on special-status species
(if applicable)
Related Management Recommendations
• weed control, especially if grazing animals
will be used for this purpose
• protection of sensitive resources such as
riparian areas or oak seedlings
Monitoring and Evaluation
• compliance monitoring (i. e. actual use
records if applicable)
• effectiveness monitoring
• evaluation of monitoring results
• management feedback
Implementation Schedule
Appendices
Who Can Help You Develop a
Grazing Plan?
Non-federal landowners who are not
individuals (i.e. agencies, corporations, nonprofits etc.) are required to engage a statelicensed Certified Rangeland Manager (CRM)
to prepare grazing plans and make related
recommendations under certain circumstances.
In situations where CRM laws don’t apply (see
below), ecologists, botanists, wildlife biologists,
livestock producers, and other practitioners
or professionals who have related experience
and academic background may be able to
help. University of California Cooperative
Extension (UCCE) Range Management
Advisors and NRCS are two excellent sources
of assistance.
Certified Rangeland Managers
Since 1995, The State Board of
Forestry has been licensing
qualified individuals as
Certified Rangeland
Managers. The intent
of the program is
to provide evidence
of professional
competency, to protect
the public interest, and to
ensure proper management
of California’s rangeland
resources as embodied in the
Code of Professional Ethics
of the Society for Range
Management.
The state license is required
for range management activities
on “forested landscapes” which are
defined as “tree dominated landscapes and
their associated vegetation types on which
are growing a significant stand of tree
species or which are naturally capable of
growing a significant stand of native trees in
perpetuity.”63
A license is required for work on
hardwood rangeland, such as oak woodland
or savanna, but not on permanently treeless
shrublands or grasslands. Activities include
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making management recommendations,
scientific studies that are available in university
developing conservation plans, grazing plans
libraries or on the internet may provide
and management plans, and other associated
useful background information for a grazing
plan. Additionally, familiarization with local
endeavors.
preserves or organizations with scientists on
Scientists and Academics
staff may be another way to access scientific
California’s rangelands have been the
information. The Nature Conservancy (TNC)
subject of study
produces “Element
and description
Stewardship
since the 1940s.64 In
Abstracts”
“One of the most important reasons to
addition, published
which include
have a grazing plan is that it becomes
research on the
management
an essential reference document to
effects of livestock
information on
guide and adapt the planning process
grazing,65 native
numerous invasive
into the future.”
herbivores,66 exotic
species and are
—Larry Ford, Ph.D. CRM # 70
plant invasions67 and
available over the
defoliation effects
internet.
on native perennial
grasses,68 to name just a few topics, provides a
Livestock Producers
bounty of information that can be used to help
Most livestock producers have spent a
predict grazing effects on grasslands and their
good deal of time observing the land where
component species.
they graze, and its response to changes in
Because every site and set of
management. Ranchers may have historic
circumstances under which grazing occurs
knowledge of a particular site and although
is unique, predicting the exact effects of
they may use different terminology or plant
grazing on a given site is difficult at best, but
names, they can often describe changes in
drawing from the many research projects and
landscape appearance and plant populations.
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Implementing a Grazing Program
Infrastructure
Certain physical improvements are
needed for managing livestock grazing. Water,
fencing, site access, and corrals for working
and loading animals are the basic necessities.
Buildings such as hay storage barns may be
useful or necessary in some cases.
Infrastructure should be evaluated soon
after, or even before, a new property that may
be grazed is acquired. Land trusts and public
agencies can end up owning small parcels
that have been divided from larger ones, and
it’s important to ensure that any site planned
for grazing has, at a minimum, a viable water
source and good access for a livestock truck.
Fencing can be constructed, but without water
and access, a property may be ungrazable.
Fencing
Boundary fencing is essential for keeping
livestock on site; cross fencing is important for
distributing and managing livestock; enclosure
or exclosure fencing is used to protect
resources that might be damaged by grazing or
to establish controls for monitoring purposes.
Fencing can be constructed from a
variety of materials including different types
of wire. The type used should be appropriate
for the kind and class of livestock and site
considerations. High tensile smooth-wire,
barbed wire, woven wire, and electrified wire are
a few of the typical types of livestock fencing.
With smooth or barbed wire, strands should be
spaced so that cattle cannot push their heads
through, as this will cause undue pressure on
the fence, shortening its life. Five or six strands
of wire should be used to prevent this.
Woven wire or “field fencing” is
commonly used for sheep and goats as it is
more effective with small animals than barbed
wire. High tensile smooth wire fencing is
usually electrified, and is best used on long
straight runs on flat-to-gently-rolling land
where few posts are needed to maximize its
economy.
Wildlife biologists and conservationists
promote the concept of “wildlife friendly”
fencing that minimizes interference with
wildlife movement patterns. Smooth bottom
wires, adequate distance from the ground to
the bottom wire for small animal movement
under the fence, and other characteristics
that allow animal movement through the
fencing are used. Such fencing, especially
on property boundaries, should be carefully
designed to ensure that it is truly effective in
controlling livestock, as young calves, lambs,
and small mature livestock also may be able
to pass through. Boundary fencing must also
be designed to meet California Food and
Agricultural Code “lawful” fence requirements.
Local fencing companies, fence material
suppliers, and NRCS staff can provide help
with fence design.
California Food and Agriculture Code69
requires that livestock be
kept from public roads
by the person who
owns or controls
them:
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“16902. Permitting livestock on highway.
A person that owns or controls the possession
of any livestock shall not willfully or
negligently permit any of the livestock to stray
upon, or remain unaccompanied by a person
in charge or control of the livestock upon, a
public highway, if both sides of the highway
are adjoined by property which is separated
from the highway by a fence, wall, hedge,
sidewalk, curb, lawn, or building.”
A livestock fence is considered “lawful”
according to Chapter 7 of this same code as
follows: “17121. ‘Lawful fence’; Wire fence;
Good and substantial fence; Cattle guards.
A lawful fence is any fence which is good,
strong, substantial, and sufficient to prevent
the ingress and egress of livestock. No wire
fence is a good and substantial fence within
the meaning of this article unless it has three
tightly stretched barbed wires securely fastened
to posts of reasonable strength, firmly set in
the ground not more than one rod apart, one
of which wires shall be at least four feet above
the surface of the ground. Any kind of wire or
other fence of height, strength and capacity
equal to or greater than the wire fence herein
described is a good and substantial fence
within the meaning of this article. The term
‘lawful fence’ includes cattle guards of such
width, depth, rail spacing, and construction
as will effectively turn livestock.” Regulations
pertaining to electrified fencing is included in
Chapter 8 of the code.
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Water
A livestock watering system includes the
source, the distribution system, and watering
locations. Water should be good quality to
ensure animal health. While livestock will
drink stagnant water if forced to, poor quality
water can lead to health problems and can
decrease water intake.
The source must produce enough water,
and the delivery system must be able to supply
the daily needs of a herd within an hour or two
because most of the animals in a pasture will
seek water at the same time. Insufficient water
can cause herd panic, where all livestock run
to a water source at the same time for fear of
not having any water left to drink. Their fears
are proven out if the water source and delivery
system cannot refill the trough quickly enough.
With troughs that stay full all the time,
animals learn to drink a few at a time, avoiding
panic and the resultant quick draw down.
Livestock drinking water requirements
vary with size and species of animal, and
throughout the year based on air temperature
and water content of forage. Heady and
Child70 report that European cattle breeds
need more water than other ungulates and that
Hereford cattle require 6.42 liters/100kg/day
(7.7 gallons/1,000 pounds/day). They suggest
that a reasonable rule is to supply 10–12
gallons per day for a cow and calf, 12–15
gallons per day for a horse, and 1–1.5 gallons
per day for a ewe and lamb.
In many cases, water must be delivered
from a source to troughs or other drinking
facilities. Although some livestock will travel
over a mile for water,71 more closely spaced
watering locations encourage better livestock
distribution. Even on small sites, more than
one water source may be needed to encourage
even grazing. Use of specific areas can be
discouraged by turning water sources off and
similarly, use of other areas can be encouraged
by providing water. Off-stream water should
always be provided in riparian pastures to
discourage heavy use of streams. Depending
on location and type of source (well, spring, or
pond) water may be gravity-fed or may require
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
pumping through pipes to troughs. Portable
water systems can be used if permanent water
sources are not available on a site, although
they require much more labor to set up and
move, and they must be vigilantly monitored
to ensure a consistent water supply. In
emergency situations, water can be trucked
in, although transportation costs may be
prohibitive.
Factors to consider in determining the
number of watering locations that should
be developed include size and shape of the
property, number of pastures or paddocks
(each pasture or paddock must include access
to water), herd size, topography, and yield of
water source. Heady and Childs72 suggest that
watering locations should not be farther than
1.3 miles apart, though Vallentine73 states
that .5 to 1 mile apart is the preferred range
in steep, rough country and that they can be
up to 2 miles apart on level or gently rolling
sites. Theoretically then, based on a 1-mile
distance between watering locations, a squareshaped 2,500-acre site could be served by one
central watering location if it could supply
adequate water for the whole herd within an
hour or two. However, far corners of the site
would likely be underutilized and areas close
to the watering location would be overutilized.
NRCS staff, UCCE advisors, contractors who
specialize in rural water systems, and ranch
materials and equipment suppliers can be
consulted for help in designing and installing
livestock watering systems.
Corrals and Chutes
Corrals and chutes are often necessary
for gathering and working livestock. Loading
on a truck, branding, and veterinary work all
require gathering animals into a small area
where they can be funneled for loading or
individual handling. Temporary corrals can
be set up, but where grazing is an ongoing
practice, permanent facilities should be
considered. The livestock operator should
be consulted about location and design of
handling facilities.
Roads and Access
Maintaining access into and within
a grazed site is important for bringing
animals on site, supplemental feeding, and,
especially on large properties, to allow the
livestock operator to check his or her animals.
Development and repair of water sources,
fencing, and other improvements also requires
vehicular access.
If livestock are trucked in, an entrance
that allows a truck and trailer to safely pull off
public roads is needed.
Ideally, an access
point should
allow a truck and trailer to drive onto a site
and turn around without impeding traffic. A
minimum 12-foot-wide (preferably 16-footwide) gate and gravel turn-around area near
corrals and buildings should be provided.
Existing ranch roads should be
maintained to keep them clear and serviceable
and prevent erosion. Areas that are not
accessible by truck may need to be served by
4-wheeled, off-road vehicles.
Barns
Barns can be useful for hay storage,
especially for livestock operations where
animals are fed alfalfa or other supplemental
feed. For example, cow-calf operators provide
supplemental feed to pregnant and lactating
mother cows during fall and winter when
forage does not provide adequate nutrition.
Barns are also useful for storage of tools and
equipment. The type of livestock operation,
distance to off-site storage, if any, and other
variables determine how important on-site
storage is.
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Fostering the Landowner/Livestock
Producer Relationship
Livestock producers are an essential
component of grazing programs. Without
the people who raise livestock commercially,
this important vegetation management tool
would not be available. Ranchers face many
constraints in today’s culture and marketplace.
From conflicts with adjacent urban neighbors,
to marginal profits, to more stringent
regulations, ranching is an increasingly difficult
business.
A good relationship between a
landowner and livestock producer may be the
most important factor in determining the
success of a grazing program and meeting
the goals and expectations of each party.
This relationship begins with the first
communication between the producer
and the landowner. When properties are
purchased with a livestock operation
on-site, continuing the existing grazing
agreement is often the best option. If
existing grazing management is not
compatible with a new landowner’s
goals and objectives, an attempt
to work out differences should be
made before seeking a new operator.
Losing grazing land can seriously
impact a livestock producer’s
operation, and it may be difficult to
find another compatible producer.
If finding the right livestock
producer seems to be an ongoing
problem, this may indicate that
grazing requirements are impractical,
that landowner expectations are
unreasonable, or that grazing fees are
too high.
The manner in which a livestock
producer is selected has a strong bearing
on the future relationship with the
landowner. Requesting bids for grazing
agreements can have disastrous results.
High bidders may be inexperienced and
may offer to pay more than they can
really afford, tempting them to overstock
a site or cut corners on maintenance. A
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more successful relationship is likely to develop
if the landowner sets grazing fees and solicits
proposals, including references. Grazing fees
should be based on a survey of local rates,
and qualified operators can be found through
advertising in local ranching publications.
References should be checked and visits to
applicants’ other grazing lands can be part of
the selection process. During this process, the
landowner should clearly describe goals and
desired grazing parameters to the producer,
and the producer should, in turn, make his or
her operational needs known to the landowner.
Private landowners may wish to simply select a
local rancher whom they know and trust.
The bottom line for a livestock producer
is that he or she must make a profit – or at
least break even – in order to stay in business.
The landowner needs to have ecological, fuel
management, or other types of goals furthered,
or he or she may not continue the grazing
program. The producer should be allowed
as much flexibility as possible, as long as
reasonable parameters are met. Likewise, a
producer must honor the landowner’s needs
and should make it clear during the grazing
agreement negotiation process if there are
requirements that will be difficult to meet.
In cases where grazing program parameters
are so restrictive that they create substantial
additional work for the livestock producer,
grazing fees should be discounted. In cases
where the landowner requires a highly
complex or inconvenient grazing program,
actual payment to the livestock producer
for providing a vegetation management
service may be in order. Clear and immediate
communication between the landowner and
the producer is essential in the event that
management problems arise.
Developing a Grazing Agreement
A grazing agreement may be as simple
or complex as needed to fit a given situation.
Different types of agreements can be used,
including leases, licenses, or permits. The
landowner’s attorney should select the type
of agreement best suited to the landowning
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entity (individual, corporation, public or
other). At a minimum, the grazing agreement
should include: the names of the parties
involved; a description of the site location;
starting and ending dates; and appropriate
legal terms. If fees are charged, these should
be stated in the agreement, along with the
method of payment. Agreements should also
spell out the obligations and rights of both
producer and landowner, grazing guidelines/
requirements, whether or not supplemental
feeding of hay will be allowed, and other
pertinent information. Attorneys, who may
not be familiar with grazing terminology
and livestock management, sometimes draft
grazing agreements. Therefore, it’s important
for land managers who interact with the
producer and are familiar with livestock
grazing to provide input to the attorney.
Specifics about the grazing program should be
integrated into the body of the lease with more
detail specified in an exhibit or addendum.
Grazing agreements should clearly
describe management practices and/or
performance-based desired outcomes.
Descriptions can be in the body of the
agreement or in exhibits, but in either case
should be clear and easy to understand.
Clauses that include terms such as “proper
use,” “good range management practices,” or
”best management practices” are sometimes
used in agreements when the drafter does not
have specific information about the grazing
program. Such phrases should be avoided as
they are subject to broad interpretation and are
so non-specific that they can be meaningless.
Grazing Fees
Rental rates are determined by forces of
supply and demand and are influenced by the
relative profitability of the livestock industry,
the supply and cost of alternative feed sources,
the productivity (feed producing capacity)
of the parcel in question, and conditions of
the lease.74 Grazing fees are most commonly
structured so that payment is by the acre per
year or month, or by the AUM, based on the
number of AUs grazing for an established
period of time. Both of these methods have
advantages and disadvantages. Regardless of
how fees are structured, performance standards
that describe desired conditions during and
at the end of the grazing season should be
specified in the lease.
Other methods for charging lease fees
include payment per whole tract, payment
per head, share of gain, and variable leases.
Payment per whole tract and payment per
head are self-explanatory terms. With share of
gain, the landowner is paid based on animal
gain. Variable leases include a base payment
rate (this could be per AUM or acre, see
below) and a variable rate that is modified
each year by the livestock price index. The East
Bay Regional Park District (EBRPD) uses this
system, adjusting grazing fees based on annual
variation in livestock prices.
Payment per Animal Unit Month (AUM)
Payment on an AUM basis offers several
advantages over a per-acre payment structure:
adjustments to the lease for changing livestock
numbers are easy to make; and temptation to
maximize stocking at the expense of the land
is removed as the lessee is paying for what
he or she uses. The downside of AUM-based
leases is that the actual use must be monitored
to ensure that fees accurately reflect usage.
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Some Relative Terms
What is “normal” maintenance?
Normal maintenance is the level of annual
maintenance necessary to keep fencing, water
developments, and other improvements
necessary for grazing in working order.
Replacement of fences, gates, water troughs
and related improvements should not be
expected as part of normal maintenance.
What is a short-term grazing agreement
and what is a long-term grazing
agreement? A 1–5-year agreement is
considered short-term. Five–10-year
agreements can be considered medium-term,
and many livestock producers may prefer
longer-term agreements of 10–20 years
or more.
What is “good quality” forage? Generally
speaking, good quality forage is highly palatable
and has adequate nutrients required by
livestock. Forage quality is determined by
species, phenological stage of forage plants, and
by seasonal changes due to weather. In order
for forage to be utilized, it must be palatable to
the livestock species, so palatability is a criterion.
If a plant is palatable enough to be ingested,
then nutritional content is important. Legumes
are relatively high in protein throughout
their life cycle, including in the seed stage.
Nutritional value of grasses varies with stage of
development, with the best nutrition typically in
the early leaf stages before flowering.75
What is “productive” land? Land productivity,
and thus forage production, is highly variable
between sites with deep, valley bottom soils and
sites with steep, exposed hillslopes. Generally,
flat ground has deeper soils and produces more
forage than hillsides or ridges that have a thin
covering of soil over rocky parent material. Land
may be productive, but if the species produced
aren’t palatable, it may not be desirable for
grazing. For example, the non-native invasive
annual grass medusa head produces a lot of
biomass, but it is highly unpalatable and thus
unproductive from a livestock forage perspective.
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Payment per Acre
Payment on a per-acre basis does not
require monitoring of animal numbers to
ensure compliance but does require that
land condition is carefully checked to ensure
that land isn’t overstocked to maximize the
producer’s return on the dollar. However, if
grazing fee rates are appropriate for the site –
in terms of pasture productivity and producer
obligations – this should not be a problem. The
number and type of livestock and season of use
should be established in the grazing agreement
with allowances for adjusting stocking rates
based on forage production fluctuations.
Otherwise, the lessee assumes the risk of
fluctuations in annual forage production.76
Exchange of In-kind Services in Lieu of
Grazing Fees
As interest in using livestock as a
management tool has increased, so has the
incidence of grazing agreements where the
producer does not pay a grazing fee. This is
especially true on small properties where it
might not be financially worthwhile for a
producer to move a small number of animals
to the site, or in situations where “nuisance
factors” such as complicated or especially
restrictive grazing prescriptions create
additional work or hardship for the producer.
The practice of trading services for
grazing fees is also used by agencies or
organizations that cannot or do not want
to receive income. A value for the grazing
rights is established, and a value for labor
and/or services provided by the producer
is also determined. An exchange is then
made. For example, within the San Luis
National Wildlife Refuge Complex, owned
by the United States Department of Fish
and Wildlife (USFWS), “cooperative land
management agreements” are used in lieu of
grazing fees. A total of 16,580 acres on three
refuges within the complex are grazed under
this type of agreement. The USFWS keeps
track of the number of animals and length
of grazing period (AUMs) for each livestock
operator and a set rate per AUM is “charged”
to the operator. At the end of the grazing
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season, the livestock operator has accrued a
deficit based on the number of AUMs times
the fee charged per AUM. In exchange, the
livestock operator purchases supplies for the
refuge complex, or provides labor toward onthe-ground projects. Labor rates are arrived at
through negotiation.77
If infrastructure is in need of
maintenance beyond what can be considered
“normal,” a partial exchange can be used to
upgrade or make major repairs, if the livestock
operator is willing and able to do so. Generally,
the longer the grazing agreement, the more a
producer is willing to invest in management
of a property. It is unreasonable to expect a
producer to invest in major infrastructure
repairs on a property with a short-term lease.
The amount of work and/or money invested
should be balanced with the length of time
needed to absorb associated costs.
Welfare Exemption for Nonprofit Landowners
Nonprofit landowners can apply
for welfare exemptions to property taxes
through the County Assessor’s office. The
State Board of Equalization (SBE) and
the County Assessor jointly administer the
Welfare Organization Exemptions. The SBE
determines whether the nonprofit organization
is eligible to receive the exemption and, if so,
issues an Organizational Clearance Certificate
for the landowner to include with claim forms
filed in any of the 58 counties of California.78
If a Welfare Exemption is granted, the
ability to earn income from the property is
terminated, which can impact the nonprofit
landowner’s capacity to enter into a grazing
agreement with a livestock producer.
Interpretation of State regulations vary by
County, and in some cases, receiving in-kind
compensation from a livestock producer
is prohibited. Even when the non-profit
landowner does not receive any compensation,
the sale of livestock that have been grazed
on Welfare Exempt land by a “non-qualified
entity” (the livestock producer), may be
considered a violation of the exemption. Before
setting up a grazing agreement, nonprofit
landowners who take a Welfare Exemption
should contact their County Assessor’s office
to discuss the Assessor’s position regarding
livestock grazing. If allowed, in-kind service
exchanges should be carefully described in the
grazing agreement.
Muir Heritage Land Trust in Contra
Costa County uses an in-kind services
exchange system with livestock operators. As
with USFWS staff at the San Luis National
Wildlife Refuge Complex, lease rates are
established and ranch livestock operators
complete maintenance or habitat enhancement
projects in exchange. Exchanges involve both
labor and materials.
No Gifts of Public Funds
Article 16, Section 6 of the California
Constitution prohibits public agencies
from making gifts of public funds,79
obligating public agencies to
demonstrate that grazing has a
public benefit in cases where no
fee or less-than-market fees
are charged. Agency
personnel should
first be confident
that a public benefit
purpose will be
fulfilled through grazing
if the agency is considering
not charging, or not receiving
in-kind compensation, for grazing.
Fee-for-Service-Grazing
In some cases, where especially laborintensive grazing plans are to be implemented,
payment for the livestock operator’s services
is warranted. Companies that provide goat
herds for brush control, for example, charge a
per-acre fee for importing and managing goats
that eat undesirable woody plants. These fees
are necessary to offset the costs of transporting
animals, providing a herder to protect and
manage animals, and setting up and moving
electric fencing, all practices that are essential
for effectively managing goats.
An example of fee-for-service grazing
occurs at The Sea Ranch in northern Sonoma
County. The Sea Ranch is a residential
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subdivision built on approximately 2,000 acres
of former agricultural land. Beginning in the
1960s, grazing was gradually phased out over
a 20-year period as development progressed.
By the early 1990s, worry over increasing fire
fuel loading and other concerns prompted
managers of The Sea Ranch Association
(TSRA) to consider methods for managing
the buildup of biomass in this complex of
forest, coastal scrub, and grassland.
Long-term landscape character was also
a concern as shrubs and trees began invading
open grasslands in the absence of grazing.
Community members did not want to lose
the pastoral landscape that had attracted them
to this beautiful coastal site. Additionally,
Bill Wiemeyer, TSRA Director of Design
Review and Environmental Management, was
concerned about loss of grassland diversity.
Different biomass management options,
including burning, mowing, and grazing
were considered. Mowing was ruled out as a
significant vegetation management tool due to
expense and the fact that many areas were not
accessible to equipment. Prescribed burns were
planned in thirteen areas of the property but
just a few of these burns were ever executed
due to logistical problems and reluctance
on the part of the California Department
of Forestry and Fire Protection (CDFFP).
TSRA’s target burn season was fall, when
wildfires are common throughout the state and
CDFFP personnel are fully occupied.
Eventually, livestock grazing was settled
on as the only reliable tool for biomass
management, and a grazing program was
initiated. Sheep were the chosen livestock
species, primarily because grazing would
take place within the subdivision and smaller
animals were
considered
to be most
appropriate in
this setting.
From a
production
standpoint,
36
there were many aspects of the site and the
proposed grazing program that presented
production difficulties. It was decided that
payment by TSRA would be necessary to
secure an appropriate rancher. Issues for the
sheep rancher included:
• low forage quality due to many years
without grazing
• grazing required labor-intensive
management including frequent
movement of small paddocks constructed
of electric fencing
• high frequency of predators including
coyotes, mountain lions, and ravens.
Several ranchers were considered for the
grazing program and a young, local producer
was selected. Issues unique to grazing within a
subdivision occasionally crop up, such as some
residents wanting to see grass blowing in the
wind during the spring, so timing the grazing
to meet the needs of both the residents and
the landscape pose special challenges. Overall,
though, Bill Wiemeyer reports that the
program is working well, although the herd
size is not yet adequate to manage the growth.
TSRA Board of Directors is considering
doubling the program. The sheep rancher is
paid per head per month, based on records and
monthly reports that he submits.80
How to Determine Grazing Fees
To establish grazing fees, local market
rates should be determined, then adjusted
upward or downward based on relative land
productivity, forage quality, “nuisance” factors,
and other pertinent information. Market rates
can be determined by contacting local agencies
or private landowners that rent land out for
grazing. Park and/or open space districts,
water districts, state and federal agencies,
and conservation landowners should be able
to provide estimates of grazing fees. Rates
may vary widely, so information about site
conditions and how rates were established
should also be sought.
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Role of Resource Conservation Districts
Resource Conservation Districts (RCDs)
are legal subdivisions of the State, formed
under Division 9 of the Public Resource Code
to provide local leadership in the conservation
of our soil, water, and related natural resources.
RCDs were originally developed in the 1930s
as the local non-regulatory mechanism for
delivery of conservation practices to farmers
dealing with soil conservation issues brought
to Congressional attention during the Dust
Bowl era. Conservation Districts exist in all 50
states; there are 103 Conservation Districts in
California.
RCDs can help facilitate grazing
on public lands because they have greater
contracting flexibility than certain government
agencies. For example, the Alameda County
and the Sotoyome RCDs are both working
through Cooperative Agreements with CDFG
to implement grazing programs on CDFG
preserve lands. In both cases, the RCD has
contracted with Certified Rangeland Managers
to have grazing plans prepared. The Alameda
RCD also has developed a lease with a livestock
producer and is managing a grazing program
on CDFG’s Byron Conservation Bank property
for CDFG. The grazing program is designed
to maintain habitat for several sensitive animal
species including California tiger salamander,
California red-legged frog, San Joaquin kit fox
(Vulpes macrotis mutica), western pond turtle
(Clemmys marmorata), and burrowing owl
(Athena cunicularia).
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G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Monitoring Grazing Use
What is Monitoring?
Monitoring is a process that includes
collection, evaluation, and interpretation of
data. Because these components can require
different sets of skills, monitoring may
require the expertise of more than one person.
Depending on the grazing program goals
and objectives, the type of monitoring being
carried out, and other variables, monitoring
may require scientific expertise and statistical
analysis. In some cases, simple photographic
monitoring may be adequate and qualitative
evaluation of the photos may be an effective
way to interpret the data.
Why is Monitoring Important?
Monitoring a grazing program is the
only way to determine if grazing is effectively
meeting established goals and objectives.
Monitoring provides the feedback to evaluate
progress toward goals and objectives in the
planning cycle. Once monitoring has revealed
trends linked to management practices, results
should be used to adjust the grazing plan and
program as appropriate
Monitoring Approaches
There are many ways to monitor grazed
sites. Methods and approaches depend
on goals and objectives, available funding,
and other factors. Monitoring can be very
simple to very complex, although complicated
monitoring plans that aren’t backed by
adequate resources will probably not be carried
out. Simpler monitoring programs that are
well matched with a budget are more likely to
be implemented. It’s much better to carry out a
simple monitoring program than to have none
at all.
Monitoring should be properly designed
to yield the type of information desired; there
is no single right way to monitor grazing
use, although there are several techniques
that are commonly used. Monitoring for
management purposes is usually less rigorous
than monitoring for experimental
purposes. Most landowners
lack the expertise or staff time
required to set up and execute
true experiments involving
replicated trials and statistical
analysis of results. However, in
some instances, university faculty
or students may be interested
in helping with monitoring if
it offers research opportunities.
Private groups, such as California
Native Plant Society (CNPS) also may be
a resource for monitoring assistance. For
example, CNPS chapters often have dedicated
volunteers who monitor rare plant populations.
Compliance Versus Effectiveness Monitoring
Two general reasons to monitor are:
1) to discover if an action complies with
expectations or regulations (compliance
monitoring); and 2) to determine if grazing
treatments are effective in achieving
desired results (effectiveness monitoring).
Compliance monitoring can be viewed as a
simple question – did what was supposed to
be done get done? For example, compliance
monitoring would be used to determine if
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a grazing lessee is following lease terms.
Effectiveness monitoring is done to determine
if management actions, such as a specific
grazing prescription, are effective in meeting
goals and objectives. In other words, is the
prescription working? An example of how
these two categories of monitoring interact is
given below:
Step 1. Goals and objectives are developed
Goal – Increase habitat for aquatic
invertebrates in vernal pools.
Objective – Increase by two the number
of species of aquatic invertebrates in
specific vernal pools by extending the
inundation periods of vernal pools from
60 to 100 days
Step 2. A grazing plan is developed to
achieve this goal and objective: the plan
prescribes cattle grazing during the green
forage season to consume exotic annual
plants that dry vernal pools up through
evapotranspiration
Step 3. The prescription is implemented:
cattle graze the site at the recommended
stocking rate during the green forage
season
Step 4. Compliance monitoring is performed
to determine if the livestock operator or
other responsible party implemented the
grazing prescription as specified
Step 5. Effectiveness monitoring is
performed to determine if the vernal pool
inundation period was extended from 60
to 100, and if two additional species of
aquatic invertebrates occupied the pool as
described in the objective
Step 6. Monitoring results are validated: the
pools’ inundation period may have been
extended, but the aquatic invertebrates
might not have occupied the pool
Step 7. Feedback is incorporated into the
grazing plan/program
If the prescription was successful in that
the two invertebrate species occupied
the pool, then the prescription should be
continued
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If the pool inundation period was
extended but the two species of
invertebrates didn’t occupy the pool, then
the shortfalls of the prescription should
be diagnosed, the prescription should be
changed and reapplied, and monitoring
should be repeated until the prescription
is determined to be effective
Conducting Compliance Monitoring
Compliance monitoring can be used
to verify compliance with a grazing lease,
mitigation agreement conditions, or other
regulatory requirements. Monitoring methods
depend on the type of information needed to
determine compliance.
Monitoring for compliance with grazing
agreement conditions could include:
• degree of utilization or other
performance-based measure such as
RDM; these types of monitoring can
be used to determine if a producer is
meeting stocking rate and season-of-use
requirements.
• animal counts/AUM verification; this
involves monitoring the number of
animals on a site and could be necessary
when payment is by AUM or to confirm
that agreed upon
stocking rates are
appropriate for
meeting goals
and objectives
• season-of-use
verification; for
grazing programs
that are not
year around, and
where the grazing agreement specifies
a particular season of use, this would
be done to determine when animals are
brought onto the site and when they’re
removed
Monitoring for mitigation compliance
could include:
• checking to make sure that a grazing
prescription designed to enhance specific
species or habitat conditions for plants or
animals was implemented; it could include
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Table 3. Sample vegetation monitoring variables
for specific purposes
PurposeVariableData Collection Methods
Detect shrub invasion into grasslands
Cover
Measure shrub cover coverage on
historic and recent aerial photographs
Detect population change
Frequency (negative or positive) in an annual wildflower species
Frequency measures
percentage of a species present in a
sample unit and is usually estimated by
plots, points, or lines
Determine amount of RDM Biomass (weight
remaining at the end of the grazing season per unit area)
such
Clip and weigh sample quadrats; visually
estimate; map by weight categories
Determine if the “coefficient of beauty” in grasslands is being maintaineds
Subjective evaluation
of beauty – possibly
colorful wildflower
display as low, medium, and high
Observation and photography
Table 4. Sample wildlife and habitat monitoring variables
for specific purposes
PurposeVariableData Collection Methods
Determine when grazing has
Vegetation Height
Measure or estimate height of
optimally affected shorebird
stubble in representative or
habitat critical areas
Determine quality of Myrtle’s
Density (number per
silverspot butterfly habitat
unit area)
Count and/or estimate the number
of adult nectar plants and larval
host plants within populated area
Determine population size of
Density (number per
Callippe silverspot butterfly
unit area) Count and/or estimate the number
of adult and larval butterflies
within populated area
Determine if grazing is Density for numbers; beneficially affecting numbers diversity can be measured
and/or diversity of vernal pool with several different
aquatic invertebrates
indices such as density,
cover, or biomass
Force the bottom edge of a dip net
along the pool bottom for a fixed
period, with each dip representing a single sample that must be replicated
to characterize populations or
communities at a particular site81
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Table 5. Sample rangeland water quality and hydrologic
monitoring variables
PurposeVariableData Collection Methods
Determine if livestock urine and/or
Parts per million of
manure are entering a stream and un-ionized ammonia
causing elevated ammonia levels
Collect water samples from above
and below livestock-affected area and
run ammonia tests
Determine if livestock are causing
Observation, volumetric
or exacerbating streambank erosion
measurements, turbidity
and resultant sedimentation
Visit site and record observations;
several kinds of turbidity sensors
and meters are available;
transparency can be measured by
the Secchi disk method
Determine if livestock grazing is
Pool depth
affecting the length of vernal pool
inundation periods
Measure pool depth in grazed and
ungrazed control plots with staff
gauge at regular intervals in spring
monitoring use records, determining
if prescribed fencing was installed, or
confirming any other aspect of a grazing
program prescribed as mitigation
In laying out a monitoring program,
care should be taken to balance financial and
staffing resources with monitoring design.
If monitoring native perennial grassland
composition changes is planned, will the
resources to follow such a long-term project be
available in the long-term?
A few examples of vegetation variables
that might be monitored for specific purposes
and appropriate general data collection
methods are shown in Table 3.
Monitoring for wildlife commonly
includes vegetation measurements (see Table
4). Habitat conditions are often evaluated,
rather than – or in addition to – the animal
itself. Habitat monitoring for wildlife species
also requires confirmation that the target
species is occupying the habitat.
Trampling, deposition of nutrients
or pathogens from animal waste, and
sedimentation from upland erosion sources
related to grazing can affect water bodies.
Often these affects are negative, but recent
research by Marty82 demonstrates that cattle
grazing can beneficially affect vernal pools.
Water quality or hydrologic monitoring
variables and methods are dependent on the type
of information desired (see Table 5). Because
Conducting Effectiveness Monitoring
Many different variables related to
vegetation, wildlife, hydrology, soils, or other
ecosystem components can be monitored
to determine grazing
prescription
effectiveness.
Changes in
vegetation
composition,
cover, frequency,
dispersion,
biomass, stubble
height, and other
characteristics can all be
measured and evaluated through monitoring.
Some vegetation changes, such as species
composition in perennial grasslands, may
occur slowly, requiring many years of careful
monitoring. On the other hand, changes in
populations of some annual wildflowers take
place more quickly, providing short-term
monitoring feedback.
42
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
many natural and human- (or livestock-)
induced processes affect water quality, it’s
important to carefully separate livestock from
other affects. If livestock impacts on water
quality variables such as ammonia or pathogen
levels are being monitored in a stream, water
samples should always be taken above and
below a suspected source of contamination.
This way, it can be determined if the
contaminants entered the stream before they
came in contact with the livestock operation in
question.
Erosion, which can be caused or
exacerbated by livestock, is related to water
quality monitoring because sediment is
a common and serious non-point source
pollutant on grazed lands. Beyond simply
using careful observation, common sense, and
knowledge of erosional processes, monitoring
erosion rates or determining exact causes is
difficult and very technical and, therefore, not
addressed here.
Common Types of Grazing Monitoring –
RDM, Stubble Height, and Percent
Utilization
Several types of monitoring are
commonly used on grazed lands to determine
if grazing complies with generally accepted
levels of use. RDM standards were developed
specifically for use in California, while percent
utilization and stubble
height standards have
been more commonly
used in other states.
The basic
differences in these
three approaches to
monitoring grazing
use are:
1. RDM
monitoring
evaluates the
amount of dry
biomass remaining
in the fall, at the
end of the grazing
season; standards are not necessarily
linked to total forage production
2. stubble height is based on height of
biomass remaining after grazing, though
it does not necessarily need to be dry;
like RDM, stubble height standards are
not based on the total forage crop, but
represent a desired condition
Predicting Fall RDM Levels
RDM monitoring is done in the fall prior to the rainy season. While the timing of fall germinating
rain is a moving target, the amount of RDM at that time can be critical for soil protection and
a favorable micro-environment for the coming years’ herbaceous plant community. If RDM is
measured earlier, an adjustment must to made to correct for losses due to decomposition.
Research has demonstrated that the amount of RDM, by weight, will average a decrease of
7% per 30-day period from the time of peak standing crop of annual herbaceous species to
occurrence of the germinating rain in the fall.83 This rate can be used to calculate backward from
the desired RDM amount in October-November to an amount that must be present earlier in
the summer. RDM disappearance at individual locations has been shown to range from a high of
13% per 30 day period to a low of no disappearance over the dry summer months in any one
year. In situations where conservative use and a higher RDM standard is appropriate or desired,
rangeland managers could utilize the higher observed rate of RDM disappearance, 13% per 30day-period to determine the amount to leave at an earlier date.84
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The Development of RDM Monitoring
Since Clawson and McDougald85 coined the
term “residual dry matter” more than 20 years
ago, it has been prescribed widely for monitoring
on grazed lands in California. RDM monitoring
has many valuable uses, both for livestock
producers and for conservation-oriented land
managers. A look at how this concept was
developed gives some interesting insights into its
potential applications.
Harold Heady, professor emeritus of Range
Management at the University of California
at Berkeley, recognized that although many
range managers and scientists acknowledged
the importance of maintaining mulch (the
dead plant materials above the soil surface
– also referred to as RDM, litter, or plant
residue) in grassland management, critical
variables such as distribution, thickness, and
occasionally the amount of mulch, had not
been examined quantitatively. In the early
1950s, he conducted an experiment at the
Hopland Field Station in Mendocino County
to examine the relationships of mulch levels
to subsequent years’ forage production and
species composition in 64 adjacent plots. The
results of this experiment were reported in
a paper titled “Changes in a California Annual
Plant Community Induced by manipulation of
Natural Mulch” that was published in Ecology.86
Heady recognized the resource protection
values of mulch as well as the advantages to
livestock producers and California’s agricultural
economy. Among the questions that this
experiment attempted to answer was: “What
is the optimum amount which will promote
maximum yearly and year-long production of
forage?” Another objective was to determine
the cumulative effects of mulch on botanical
composition. Study site vegetation was
composed primarily of annuals with scattered
broad-leaved perennials and occasional
individuals of purple needle grass (Nassella
pulchra). It’s important to note that, although
he supposed the importance of mulch in
protecting soil from erosion, his experiment did
not quantitatively evaluate this aspect.
44
The experiment involved manually manipulating
mulch levels within plots by hand clipping
to various levels. Over the four years of the
experiment, Heady found that:
• increasing amounts of mulch on the soil
immediately before the fall rains led to
an increase in herbage production the
following spring
• biomass production increased with
increased weight of mulch between 1,200
and 2,400 pounds
• some species responded to mulch
treatments, and some didn’t
• mulch has a direct effect on composition,
and some species were favored when all
mulch was removed, others were favored
when none was removed, and a third
group reached maximum composition
with intermediate mulch levels; for
example, California goldfields (then Baeria
chrysostoma, now Lasthenia californica) were
very abundant with no mulch and were
absent where mulch was heaviest; conversely,
soft chess (then Bromus mollis, now B.
hordeaceus) was the only plant that increased
significantly in percent composition with the
heaviest mulch treatments; legumes were
most abundant at intermediate mulch levels
• although he observed evidence of erosion
on the plots where all mulch was removed,
there was no evidence of erosion on other
plots; the erosion evidence disappeared on
the bare plots three to four weeks after the
first rains
In the late 1970s, Heady and four graduate
students, Jim Bartolome, Michael Stroud, Glenn
Savelle, and Mike Pitt conducted another
important RDM experiment. This experiment,
which again involved manipulation of mulch
levels, took place on nine sites throughout
California. The purpose was to demonstrate
how the mulch layer can be managed to
significantly influence the subsequent year’s
forage production. Findings included:
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
• perennial grass sites with annual
precipitation over 40 inches should
probably be managed as perennial
grasslands with attention paid to plant vigor,
season of grazing use, and maintenance of
at least 1,000 pounds per acre (the RDM
standard for high rainfall areas has been
adjusted upward in recent years) of mulch,
preferably more, at the end of the grazing
season
• in mid-rainfall annual ranges, mulch levels
are the most important factor
• on drier sites, maintenance of sufficient (this
was not quantified) mulch to prevent soil
loss is most important
W. James Clawson and Neil McDougald
presented numeric RDM standards for the
first time in 1982,87 in the proceedings of the
Western Section, American Society of Animal
Science. As a Range Specialist with Agronomy
and Range Science Extension (Clawson) and
Madera County Farm Advisor (McDougald),
their work focused on livestock production on
annual rangeland, which contributes 80 percent
of the range forage for California’s livestock
industry.
They coined the term “residual dry matter”
and suggested guidelines for minimum or lower
threshold RDM levels for California. These
ranged from about 270 pounds per acre to
1,070 pounds per acre, depending on annual
precipitation. They acknowledged that the
amount of RDM required for a given site can
be quite variable and encouraged managers to
test minimum guidelines and develop their own
levels to meet the requirements of specific site
conditions. They stated, “Too much residual dry
material or a dense mulch results in a thatch
which inhibits early response of new forage
growth. Maintenance of seeded annual legumes
and filaree (Erodium spp.) abundance requires
adequate but lower amounts of residual dry
material.” This paper also linked the idea of
using broad categories to describe grazing
impact on landscape appearance and stubble
height: light grazing leaves three or more inches;
moderate grazing leaves two inches; and heavy
grazing leaves less than two inches with areas
of bare soil visible from 20 feet away.
That same year, University of California
Cooperative Extension Leaflet 21327, titled
“Guidelines for Residue Management on
Annual Range” was authored by Clawson,
McDougald, and Don Duncan, a US Forest
Service Range Specialist. This publication
included similar information, but suggested
minimum guidelines (again, to be tested sitespecifically) ranging from 200 – 1,250 pounds
per acre.
RDM guidelines recently have been reviewed
and updated by the University of California
Division of Agriculture and Natural Resources
in Rangeland Monitoring Series Publication
809288 with more consideration given to the
perennial-rich coastal prairie. RDM guidelines
for open coastal prairie (with no tree cover)
now range from 1,200 – 2,100 pounds per
acre, depending on slope.
RDM monitoring techniques include:
• Comparison to Photographs. This is a
simple and quick method that involves
visual comparison of field conditions to
photographs of known RDM levels
• Clipping Plots. RDM is clipped within
one-square-foot quadrats, weighed, and
converted to pounds-per-acre
• Visual Estimating. This is usually done in
combination with clipping, which is used
to calibrate the monitor’s eye; once the
monitor is able to accurately make visual
estimations, clipping is no longer necessary
• Mapping. Mapping the pattern of RDM
levels on a site has been used to graphically
depict livestock-use patterns so that
managers can improve animal distribution;89
visual estimating is used to mark RDM
categories – low, medium, or high RDM
– or weight ranges, on a map
See Appendix for sources of information on
RDM monitoring.
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45
Warning:
Be Aware of Monitoring
Limitations
Detecting long-term change is difficult
because of the high degree of interannual
variation in grasslands that tends to override
longer-term patterns of change. Due to the
high degree of annual variability, an adequate
baseline or record of characteristics takes
longer than one year to build in grasslands.
3. percent utilization requires knowledge
of the total forage crop, with a certain
percentage allowed for removal by livestock
RDM and stubble height monitoring
have useful applications for conservation-based
grazing as either type of monitoring can be
customized to correspond to desired landscape
conditions. For example, if a particular native
wildflower species is known to thrive with very
low RDM levels, then site-specific standards
can be developed to represent conditions
required for that species.
“Stubble” or grass height standards
can be used similarly. Suitably low grass
height is important for maintaining habitat
for a number of wildlife species including
burrowing owls. Plumpton90 found that in
Colorado, burrowing owls nested in black
tailed prairie dog (Cynomys ludovicianus)
burrows that were farther than expected from
the nearest perch; grass height was shorter at
nest sites than at non-nest sites.
Utilization measurements were originally
developed in midwestern tall-grass prairies,
and there is little evidence to support its
application in arid and semi-arid areas.91
Measurements are based on the idea that
if grazing is in excess of a certain critical
amount, desired plants will lose vigor, produce
less herbage, and eventually die.92 The term
“proper utilization” is used to describe the
level of defoliation that can occur while still
maintaining range productivity or improving
range conditions. Identifying key plant species
and their associated “proper use factor” is
an essential part of meaningful utilization
46
measurements. This technique is sometimes
employed to measure browsing use on woody
riparian plants where RDM and stubble
height measurements don’t apply.
An example of how these standards
are applied is provided in the Bureau of
Land Management’s (BLM) “Northwestern
California Standards for Rangeland Health
and Guidelines for Livestock Grazing
Management”.93 In this document, BLM
prescribes:
• Stubble height. A four-to-six inch
minimum stubble height should remain
at the end of the grazing season in most
riparian areas.
• Percent utilization. No more than 20
percent of key riparian tree and shrub
species should be utilizedin those areas
where the presence of woody riparian
species is necessary to meet standards.
• RDM. Specific RDM levels should
be maintained on upland slopes; levels
vary from 400–2,000 pounds per acre
depending on rainfall and slopes.
Minimal Monitoring Approaches
If staffing or financial constraints
are obstacles to carrying out a structured
monitoring program, very rudimentary
monitoring is better than none. At a
minimum, visiting the site, recording
observations, and adjusting management
based on these observations is preferable to
not conducting any monitoring. Photographic
monitoring, especially if photographs are taken
in the same location over a period of time, is a
good way to document changes in landscape
appearance. Videos or movies taken with a
digital camera also can be used.
Photographic monitoring
Photographic monitoring can be done in
a variety of ways but it should, at a minimum,
incorporate the following:
• Permanent photo points. Permanent
photographic monitoring locations should
be established to ensure that photographs
can be successfully compared over time.
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Monitoring Riparian Grazing
Riparian grazing programs can be evaluated on the basis of whether they improve
degraded riparian areas or maintain riparian areas in good-to-excellent condition.
Where target species are involved, whether plant, animal or both, monitoring the
status of those species within the riparian area will be critical in evaluating the
success of a particular riparian grazing program. Managers must be prepared to
change key indicator species or forage utilization guidelines as needed to meet
defined objectives. For example, a grazing prescription developed to protect sedge
reproduction in a given stream reach may not adequately allow willow recruitment.
If establishing willows becomes a management priority on this reach, a change in
season of use, or a period of livestock exclusion, may be necessary. Some species,
anadromous fishes, for example, may not respond to local riparian improvement
when larger landscape processes or population dynamics override local conditions.
At the same time, improvement in local conditions on multiple sites throughout a
watershed can lead to system-level improvement in patterns and processes.
Adding to the complexity of managing and monitoring the response of
riparian pastures is the fact that watersheds are dynamic, and may change quite
independently of grazing treatments. Managers of riparian pastures need to keep
this clearly in mind as they implement and adapt their management plans through
years of drought, flood and average rainfall. Documentation of successful – and
unsuccessful – riparian grazing strategies is an important contribution that riparian
graziers can make to land management in the region.94
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47
Photo points can be set using a global
positioning system (GPS), a naturally
occurring monument such as a large rock,
or a man-made marker.
• Recorded data. Information should
be recorded to ensure that the exact
photograph can be reproduced in the
future. The location should be carefully
recorded, preferably on an aerial
photograph and/or on a monitoring form,
even if using a GPS. Camera focal length
should also be noted as well as camera
distance from the focal point of the
photograph.
• Identify the photographs. Each
photograph should include the subject,
date, photograph location number or
other reference. This can be done by
writing this information on a small
chalkboard or whiteboard that is propped
up in the foreground of the photo.
• Include landscape features. If possible,
photographs should include landscape
48
features that can be identified for exact
relocation in the future. A photograph of
a hillside with a tree in it is much easier
to duplicate than one of a generic, grassy
hillside. If possible, include the horizon
line to facilitate relocating the photopoint
within the landscape.
• Identify scale. A short pole or board with
the halfway mark identified (this can
be done by painting half of the stake a
different color or with tape) should be set
in the foreground of the photograph to
provide a scale reference. This is especially
important if vegetation height is being
recorded.
Woody vegetation change and other
landscape features can be monitored over time
through aerial photograph interpretation.
Aerial photos of the same scale can be
compared, or actual point sampling of photos
using a dot grid can be used. Guidelines for
photographic monitoring are widely available
on the internet.
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Select Habitat Types
Vernal Pool Grasslands
Vernal pools are unique seasonal
wetlands that support diverse and often rare
and endangered native plant and animal
species.95 They fill with water during the rainy
season and dry up in the spring as rainfall
ends. They are threatened and are disappearing
rapidly in California.96
Within the SRCD, vernal pools occur
throughout the Santa Rosa Plain in areas
where clay soils and a hardpan layer restrict
water percolation. They also occur in scattered
locations on the mountains that surround the
Plain. Most vernal pools occur on flat and
nearly flat ground, so many of the natural vernal
pools in this area have been destroyed by urban
development and crop farming. In recent years,
artificial vernal pools have been constructed
within the Santa Rosa Plain to mitigate for the
loss of natural pools by development.
In the past, preserve managers have
tended to remove livestock from vernal pool
preserves to protect them from damage.
Cattle grazing has been implicated as a
major contributing factor to the decline of
four vernal pool crustaceans listed under the
U.S. Endangered Species Act but with little
supporting scientific data.97 However, scientists
and conservationists have observed endemic
vernal pool species disappear after grazing
removal in numerous Bay Area locations.98
Results of a recent study on grazing
of vernal pool grasslands in Central
California indicate that cattle
grazing can have dramatic
beneficial effects on vernal pool
flora, fauna, and hydrological
regimes. This study was
performed on The Nature
Conservancy’s (TNC)
Cosumnes River Preserve
by TNC Project Ecologist
Jaymee Marty. Marty’s
study compared timing of grazing in vernal
pool grasslands to determine its effects on
native plant and aquatic faunal diversity. The
study involved vernal pools across two different
soil types and a wide range of pool sizes and
depths on a site where cattle had grazed for
the past 100 years. Marty removed cattle either
completely or seasonally from groups of pools
and compared the response of plant species
cover and diversity, pool hydroperiod – the time
period that pools are filled with water – soil
compaction, and aquatic invertebrate diversity
to pools grazed at historic levels. The entire
site was grazed from October to June at a
stocking rate of 1 AU/6 acres. Treatments
were: ungrazed; dry-season-grazed (October/
November and mid-April–June); wetseason-grazed (December–mid-April); and
continuously-grazed (October–June).
After three years of treatment, pools in
areas where grazing was removed had 88%
higher cover of exotic annual grasses and 47%
lower relative cover of native species than pools
grazed at historic levels (October through June
at a rate of 1 AU/6 acres). Marty found that
in pools that were released from grazing, pool
inundation periods were reduced by 50–80%,
making it difficult for some vernal pool species
to complete their life cycles.
She also found that continuouslygrazed pools had the highest relative cover
of native species across all three years of the
experiment. Relative cover in the pool zone
was not affected, but relative
cover of native species in the
edge zone was 80% higher
than in ungrazed pools
and 160% higher than
in the ungrazed pools in
the upland zone. Exotic
grass cover increased
dramatically in the
pools where grazing
was removed during
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49
the experiment. A strong increase in cover
of grasses relative to cover of forbs was
measured in the ungrazed treatments.
Native plant species richness
either increased or remained the
same over the three years of the
experiment in the continuouslygrazed, wet-season-grazed, and
dry-season-grazed treatments,
but it declined in the ungrazed
treatment. This represented a
loss of 25% of the average native
species richness in the edge and
upland zones over the three years
of the experiment.
Marty’s field experiments
indicate that when cattle are removed
from grazed vernal pool grasslands,
diversity can decline and non-native
species abundance can increase. Marty
believes that “decline in native plant cover
and diversity in the ungrazed treatments was
most likely caused by the significant increase
in grass cover” through competition for
soil moisture and light resources. Increased
evapotranspiration rates due to high annual
grass cover may be the cause of dramatic
decrease in pool inundation period, though
Marty also theorized that decreased soil
compaction in the absence of livestock could
have negatively influenced pool hydroperiod.
Invertebrate taxa richness also declined in
pools that were ungrazed or had shorter
grazing periods, most likely due to altered pool
hydrology, especially an increase in the number
of times that pools dried up.
Her results also show that prolonged
inundation in the absence of grazing is not
enough to keep exotic species out of the pools.
Edge and upland zones (compared with pool
bottoms) were the most negatively affected by
grazing removal with marked declines in native
species richness and relative cover of natives.
Coast Range Grasslands
Grasslands that occur near California’s
coast often include a higher proportion of
perennial grasses than drier, inland sites and
50
have thus been termed “Coastal Prairie.”
California’s grasslands have been described
as being composed of three major types:99
the Valley Grassland; the California Annual
Grassland; and the Coastal Prairie, which is
dominated by native perennial grass species
that vary from north to south and with
distance from the coast. This division of
grassland types into classifications that imply
a sharp division between inland and coastal
areas, as well as dominance by perennial versus
annual species ignores the vast acreage of
transitional grasslands within the SRCD and
other areas of near-coastal California. They
imply a distinct separation when, in fact, the
gradient of maritime influence is often gradual.
Jackson and Bartolome100 have recently
proposed adding a third grassland subtype, the
Coast Range Grassland, which is transitional
between inland (Valley) and coastal (Prairie)
grassland types. This term may be the best
label for near-coastal grasslands within the
SRCD, which typically include
a varied mixture of native
and non-native, perennial
and annual species.
Management for Native
Perennial Grasses
Goal-driven grazing
management relinquishes
the need to describe grassland
vegetation according to particular
terms or classifications. Instead,
it can address certain species or
guilds of plants, particular wildlife
species, landscape function, or any
number of other elements. The State
Coastal Conservancy and many
resource managers share a strong
interest in preserving and enhancing
native grasses. Restoration of native
species in California grasslands is
a conservation goal in many parks,
reserves, and other public lands.101
Generally, perennial grasses
benefit from seasonal or periodic
grazing rather than continuous
year-round grazing. Unlike annuals,
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
which rely on copious seed production
and germination of many new plants each
season, perennials can live for many years.
They normally produce less seed that annuals
and are slower to germinate and grow as
young plants, so the health and longevity of
individual plants is much more important.
When their leaf area is temporarily decreased
through grazing, the plant’s ability to
photosynthesize and make carbohydrates
is reduced, which results in root dieback.
Severe, repeated grazing can weaken or kill
some perennial grasses but complete absence
of grazing can diminish their overall health
because grazing stimulates vigorous new
growth that actively photosynthesizes.
Perennial grass species vary in their
responses to grazing. Low-growing species
and those that spread by rhizomes or stolons,
tend to be more resistant to heavy grazing than
bunch grasses.
Unfortunately, limited research seriously
restricts the ability to generalize about grazing
practices for enhancing or restoring native
grass species.102 This makes it difficult to plan
grazing programs to favor native grass species
without site-specific experience and data.
There are many reasons that reliable data on
enhancement or restoration of native grasses is
limited. These include:
• long-term studies required to detect
changes in grassland species composition,
especially with native species,
requires long-term time and funding
commitments
• observational studies have limited value
because of the difficulty in separating
grazing effects from other effects; a
common pitfall is the practitioner’s desire
to see a positive outcome
• there are many variables that affect
a grazing regime and a multitude of
possible combinations, yet a limited
number of variables can be compared in
any one study
• different species may respond differently
to a particular grazing regime – what’s
good for purple needlegrass may not be
what’s good for California oatgrass
• native and exotic species within a guild
may respond similarly; for example,
grazing responses of California
oatgrass versus Australian oatgrass or
purple needlegrass versus a non-native
needlegrass (Nassella formicarum) may be
analogous
Identification of the habitat needs and
responses to grazing of individual native
plant species must be carried out on site- and
species-specific bases.
Riparian Systems
Riparian areas are made up of rivers,
streams, and creeks, their floodplains,
vegetation, and dependant wildlife species.
They are highly resilient, dynamic systems with
naturally high levels of disturbance.103 Riparian
areas concentrate nutrients, water, and
energy, making them highly productive. They
include waterways that flow all year as well as
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
51
Rules of Thumb for Riparian Grazing
• Off-stream water should be provided so animals don’t have to enter the stream to drink. If
this isn’t possible, controlled stream access points should be provided to encourage animals to
drink in specific, managed locations.
• Supplements should be strategically placed away from riparian areas to encourage grazing in
upland areas.
• Riparian grazing should be avoided when streamside vegetation is the only green feed in the
pasture.
• Areas near streams should never be used to concentrate livestock. Corrals, paddocks, and
feed racks should never be located near or within stream channels.
• Livestock should be kept off saturated pastures near streams. Grazing on saturated
streambanks can exacerbate erosion.
• Timing of grazing will vary depending on seasonal weather patterns and grazing objectives.
• Where human contact with pathogenic organisms are a concern, Cryptosporidium and other
pathogen inputs into water should be minimized. Calves under six months of age should not
be present when water is flowing.
• Where ground- and shrub-nesting bird protection is a riparian pasture management
objective, grazing should be eliminated, reduced, or closely managed during nesting season
(March to July) to prevent trampling of nests, maximize the understory habitat value, and
minimize foraging habitat for cowbirds. Alternatively, if riparian grazing is necessary during this
time of year to meet other management goals, grazing should begin before March to prevent
birds from building nests that could be trampled later104. A thick riparian understory can
also be crucial to successful rearing of young birds, so excluding part of the riparian area to
allow understory development could also be a solution. The Riparian Habitat Joint Venture105
suggests establishing wide riparian pastures and moving cattle often to avoid the impacts of
year-round grazing on nesting birds.
seasonal or ephemeral drainages. Healthy
riparian areas include structurally diverse plant
communities composed of graminoids, forbs,
shrubs, and trees. These varied types of plants
provide a diversity of habitats for a variety of
wildlife, including insects, amphibians, reptiles,
fish, birds, and mammals. While many species
depend entirely on riparian areas, many more
use them during only a portion of their life
cycle. Riparian areas are also essential to the
proper functioning of watersheds. They act like
the plumbing within a watershed, transporting
concentrated water flows through large drainage
52
networks and moving, filtering, and storing
sediment and nutrients.
Serious damage has been caused to
riparian areas by unmanaged or poorly
managed grazing. Although new perspectives
on riparian grazing have improved riparian
management over the past 20 years, plenty of
examples of grazing-induced riparian damage
can still be found locally and throughout the
West.
Given this, it’s natural to wonder why
riparian grazing is even considered here.
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Although poorly managed livestock grazing
within riparian areas can cause serious resource
damage, at the other extreme, complete
exclusion of grazing can also be ecologically
damaging by allowing exotic plant species
to flourish unchecked. From the perspective
of livestock production, riparian areas are
especially valuable as they are often highly
productive due to deep, rich soils and abundant
moisture. Riparian pastures can stay green,
providing nutritious forage for weeks after
upland pastures have dried up.
Riparian Grazing Management
By preventing or carefully controlling
access to streams during critical periods,
riparian areas can provide desired habitat
and other environmental values as well as
providing forage at appropriate times of year.
After an extensive survey of riparian grazing
literature, Creque106 concluded that the
common threads in successful riparian grazing
strategies throughout the West are minimizing
grazing time in riparian areas and maximizing
flexibility and control by managers.
Fencing, which provides control over
livestock, is an essential component of
successful riparian grazing management. Several
different approaches can be taken. Complete
livestock exclusion with fencing has been the
protection method of choice for many public
agency landowners and resource agencies in
recent years. The other option is development
of riparian pastures where cross fencing is
used to create grazed pastures that include
riparian areas. A slight variation on these two
approaches is the occasional grazing of excluded
riparian corridors, which can be done to manage
biomass within narrow boundaries.
Management strategies that do not
involve fencing can also be used, but are much
less likely to provide adequate control over
livestock. Techniques such as placing mineral
licks and other attractants well away from
riparian areas and developing upland water
sources may reduce the time that animals
spend in riparian areas,107 but do not provide
enough control over animals for effective
riparian protection in many cases.
The exclusion and riparian pasture
approaches to grazing management each have
advantages and disadvantages, which should
be carefully considered before choosing one
over the other. In fact, alternating periods of
limited use with periods of complete exclusion
may be the best management approach in
some cases. Site characteristics, management
goals, and human resources available for onsite management should be weighed before
deciding on a strategy.
Exclusionary Fencing
Exclusionary fencing is used to protect
narrow corridors adjacent to riparian areas.
On private lands where maximizing forage
availability is a priority, excluded areas are
usually narrow to minimize the amount of
land
that is taken
out of pasture.
Exclusionary fences are
commonly placed within
about 10–20 feet of the “top of
bank.” This prevents animal access,
and direct animal waste deposition,
in the creek, and thus protects water
quality. It also protects banks from erosion
by trampling and safeguards woody vegetation
from animal damage. Disadvantages to this
type of fencing include :
• constriction of channel geomorphology
• establishment of exotic weeds that
thrive in the absence of grazing such as
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
53
•
•
•
•
Himalayan blackberry (Rubus discolor)
and poison hemlock; western riparian
areas are subject to invasion by a growing
number of non-native plant species, and
weed growth will often surge
after livestock exclusion;108 brush
and weed management are
among the greatest potential
environmental benefits that
managed grazing offers to
riparian areas109
accumulation of thatch can
decrease grassland species
diversity, favoring species that
are adapted to high thatch
conditions
potentially high fence maintenance
demands from damage due to flooding
can restrict access to riparian areas for
some wildlife species
loss of forage resources
Despite these disadvantages, exclusionary
fencing may be preferred in some situations,
primarily because it requires less management
oversight than do riparian pastures.
Riparian Pastures
Riparian pastures contain riparian areas
that are integrated with the grazing unit.
Rather than completely excluding livestock,
the riparian area is carefully managed in
conjunction with adjacent uplands. Although
more management oversight is needed,
riparian pastures can have several advantages
over complete exclusion. Advantages include:
• less likelihood of establishment of certain
exotic plant species
• better biomass management and less
thatch buildup
• dynamic channel morphology permitted
without flood damage to fencing
• less impact on wildlife movement
Disadvantages, which are most likely
to become problems with inadequate
management oversight, include:
• damage to young, woody riparian plants
(depending on season)
54
• erosion/water quality impacts (depending
on time of year)
In hot weather, livestock are especially
attracted to the shade and water offered by
riparian areas which usually have green
forage later in the year than uplands;
this serves as an additional
attractant. If riparian grazing
occurs during summer weather,
special attention should be taken
to prevent animal congregation in
riparian areas.
Actual grazing prescriptions
for a given riparian area should
be site-specific based on biological,
ecological, hydrological, and
geomorphological characteristics, and
management goals. Variables such as timing,
duration, and frequency of grazing, stocking
rate, kind and class of animal, utilization
level, and animal distribution are all subject
to management control. They can be adjusted
to meet management goals and riparian
condition objectives. Determining appropriate
timing of grazing is perhaps the most difficult
aspect of riparian grazing. Restricting livestock
use of riparian areas to infrequent, short
periods minimizes the potential for negative
impacts. Ideally, riparian pastures should be
of a size that will allow the herd to make use
of available forage over a few days, allowing
ample regrowth of vegetation between grazing
periods.110
Grazing should be restricted to times
when streambank soil moisture is low to
minimize streambank erosion and prevent
bank shearing.111 In the SRCD, riparian
area soils may not be firm and dry enough
to prevent streambank damage by livestock
until fairly late in the spring. However,
short, dry periods during the rainy season
may create appropriate conditions for short
periods of grazing. During the green forage
season, animals are not likely to be attracted
to streambanks, especially if off-stream water
sources are provided.
If woody vegetation is young or
newly established, livestock may need to
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
be completely excluded from the riparian
area for several years, depending on plant
species of concern and their growth rates. For
best protection, grazing should be avoided
or minimized during the summer when
herbaceous species are dry and woody species
are green and most attractive. Herbaceous
riparian vegetation is important for filtering and
trapping sediments and nutrients, providing soil
cover, and for providing habitat for grassland
plant and animal species. Stubble height
guidelines are used by some public agencies
for managing riparian grazing use. Common
stubble height guidelines allow for grazing
down to three inches in height and allowing
regrowth to six–eight inches before animals
can be returned to riparian pastures. However,
Lile et al.112 point out that direct links between
herbaceous stubble height and specific riparian
resource goals are not clearly illustrated in the
published scientific literature. These somewhat
arbitrary numbers may have little real meaning
in terms of riparian condition.
Selection of season of use should also
involve consideration of soil conditions to
limit compaction and damage of streambanks,
and the vulnerability of key plant species to
defoliation at particular periods of the year.
The protective role of vegetation during
periods of high flow, as well as forage
availability, palatability, and nutritional value
throughout the year must also be considered in
the design of a riparian pasture management
strategy.113
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
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56
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Conclusion
This handbook addresses many issues
related to the complex and fascinating topic
of grazing. Hopefully, it will help interested
resource managers start grazing programs on
appropriate lands. It should also be useful for
informing and adapting existing grazing use
to meet natural resource goals and objectives.
There are many other sources of
information on grazing and related issues,
from range management text books, to
research papers, to scientific journals. Many
of these resources are available on the internet.
One of the best and easiest ways to learn more
about grazing is to talk to experienced people.
The UCCE, NRCS, and RCDs all have
personnel who can help. These agencies have
offices throughout California and are only a
phone call away. The Appendix includes a list
of information sources related to many of the
topics covered in this handbook.
Last but not least, local livestock
producers are also a valuable resource. They
understand the economic and practical
limitations of applying scientific information
to the land. Without them, this valuable
management tool could not be implemented.
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
57
58
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Appendix
Related Organizations and Sources of Information
California Grasslands
California Native Grasslands Association.
Various information including bibliography.
Visit www.cnga.org
Coastal Training Program. Coastal prairie,
grasslands monitoring and management
and other related topics. Visit www.
elkhornsloughctp.org/reference
Grazing and Range Management
Natural Resources Conservation Service.
The NRCS provides information on many
topics including soils, grazing, grasslands, and
related.
For information specific to California, visit
www.canrcs.usda.gov and search by topic.
The NRCS National Range Handbook is
accessible on line at http://www.glti.nrcs.usda.
gov/technical/publications/nrph.html
Society for Range Management. Publications
and other information about range
management in the U. S. and other countries.
Visit www.rangelands.org.
Society for Range Management, California/
Pacific Section. Information about Certified
Rangeland Managers and section meetings.
Visit www.casrm.org
Certified Rangeland Managers. For more
information about regulations pertaining to,
visit: www.fire.ca.gov/CDFBOFDB/pdfs/
1600Regulations.pdf
www.fire.ca.gov/CDFBOFDB/pdfs/PRC750.
pdf
University of California Cooperative
Extension. Provides research-based
information on range livestock production
and management, rangeland water quality,
Integrated Hardwood Range Management
Program, wildlife management, and livestock
health. Visit http://danr.ucop.edu/uccelr/
uccelr.htm
Understanding Livestock Grazing Impacts.
Visit www.grazingimpacts.info
Livestock
California Cattlemen’s Association. Visit
www.calcattlemen.org
California Wool Growers Association. Visit
www.woolgrowers.org
California Dairy Herd Improvement
Association. Visit www.cdhia.org
American Boer Goat Association. Visit
www.abga.org
American Dairy Goat Association. Visit
www.adga.org
Vernal Pools
California Vernal Pools. Information and
resources about vernal pools. Visit www.
vernalpools.org.
RDM Monitoring
Rangeland Monitoring Series Publication
8092: California Guidelines for Residual Dry
Matter (RDM) Management on Coastal and
Foothill Annual Rangelands.
http://californiarangeland.ucdavis.edu/
monitoring_series(PDF).htm
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
59
Residual Dry Matter (RDM) Monitoring
Photo-Guide Wildland Solutions Field
Guide series. Available from Keith Gunther
of Wildland Solutions. Visit
www.wildlandsolutions.com
Photographic Monitoring
Ground-based Photographic Monitoring.
www.fs.fed.us/pnw/pubs/gtr503/
60
Plant and Animal Population Monitoring
Monitoring Plant and Animal Populations:
A Handbook for Field Biologists. 2001.
Caryl Elzinga and Dan Salzar. Available at
www.blackwellpublishing.com
Special-status Species
Recovery Plans for Special-status Species
are available from the U. S. Fish and Wildlife
Service. Visit www.fws.gov/sacramento/es/
recovery_plans.htm
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Notes
1.
2.
3.
S.W. Edwards, “A Rancholabrean-Age, LatestPleistocene Bestiary for California Botanists,” Four
Seasons 10 (2)b (1996): 5-34.
S.W. Edwards, “Observations on the Prehistory and
Ecology of Grazing in California,” Fremontia 20
(1992): 3–11.
L.D. Ford and G. F. Hayes, “Northern Coastal
Scrub and Coastal Prairie” in Terrestrial Vegetation of
California, 3rd ed., ed. M.G. Barbour, T. Keeler-Wolf,
and A. Schoenherr (Berkeley: University of California
Press, in press).
4.M.K. Anderson, Tending The Wild: Native American
Knowledge And The Management Of California’s
Natural Resources (Berkeley: University of California
Press, 2005).
5.
6.
7.
8.
9.
J.K. Lewis, “Range Management Viewed in the
Ecosystem Framework,” in The Ecosystem Concept in
Natural Resource Management, ed. G.M. Van Dyne
(New York: Academic Press, 1969), 97–187.
“The Geography of California,” [http://www.netstate.
com/states/geography/ca_geography.htm].
Grey Hayes, telephone conversation with author, 9
February 2006.
“California Dept. of Forestry and Fire Protection
Land Cover Mapping and Monitoring Program,
LCMMP Vegetation Data,” [http://frap.cdf.ca.gov/
data/frapgisdata/select.asp], 2005.
G. Hayes, and K. D. Holl, “Cattle Grazing Impacts on
Annual Forbs and Vegetation Composition of Mesic
Grasslands in California,” Conservation Biology 17
(2003): 1694-1702.
10. Wendy Eliot, personal communication with author, 9
February 2006.
11. See note 3 above.
12.Ibid.
13. J. T. Howell, Marin Flora: Manual of the Flowering
Plants and Ferns of Marin County, California
(Berkeley: University of California Press, 1970).
14.Tony Nelson, written communication with author, 8
May 2006.
15. D. F. Balph and J. C. Malecheck, “Cattle Trampling of
Crested Wheatgrass under Short-duration Grazing,”
Journal of Range Management 38 (3), (1985): 226-227.
16. Rex D. Pieper, “Ecological Implications of Livestock
Grazing” in Ecological Implications of Livestock
Herbivory in the West, ed. Martin Vavra, William A.
Laycock, Rex D. Pieper (Denver: Society for Range
Management, 1994), 177–211.
17.I. Noy-Meir, M. Gutman, and Y. Kaplan, “Responses
of Mediterranean Grassland Plants to Grazing and
Protection,” Journal of Ecology 77 (1989): 290–310.
18. D. D. Briske, “Developmental Morphology and
Physiology of Grasses,” in Grazing Management: An
Ecological Perspective, ed. R.K. Heitschmidt and J. W.
Stuth (Portland: Timber Press, 1991), 85–108.
19. See note 16 above.
20. J. F. Vallentine, Grazing Management (San Diego:
Academic Press, 1990).
21. Jeffrey Creque, Ph.D., written communication with
author, 8 May 2006.
22. Harold F. Heady and R. Dennis Child, Rangeland
Ecology and Management (Boulder: Westview Press,
Inc., 1994).
23. Jerry L. Holechek, Rex D. Pieper, and Carlton H.
Herbel, Range Management: Principles and Practices
3rd ed. (Englewood Cliffs, New Jersey: Prentice-Hall,
Inc. 1998).
24. See note 20 above.
25.Adapted from National Range and Pasture Handbook,
USDA Natural Resources Conservation Service
Grazing Lands Technology Institute, 2003.
26.Adapated from Vallentine, Grazing Management.
27. National Range and Pasture Handbook, USDA Natural
Resources Conservation Service Grazing Lands
Technology Institute, 2003.
28.Terry Palmisano, written communication with author,
17 February 2005; California Fish and Game Code,
Section 3950-3961.
29. J. W. Bartolome, et al., “California Guidelines for
Residual Dry Matter (RDM) Management on
Coastal and Foothill Annual Rangelands,” University
of California Division of Agriculture and Natural
Resources, Publication 8092 (2002).
30. See note 22 above.
31.N. K. McDougald et al., “Estimating Livestock
Grazing Capacity on California Annual Rangeland,”
UC Davis Range Science Report 29 (1991).
32.C. D’Antonio et al., UC Berkeley Department of
Environmental Science, Policy, and Management,
“Ecology and Restoration of California Grasslands with
Special Emphasis on the Influence of Fire and Grazing
on Native Grassland Species,” Unpublished report for
David and Lucille Packard Foundation (2002).
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
61
33. R. F. Follett and G. E. Schuman, “Grazing Land
Contributions to Carbon Sequestration,” in Grassland:
a Global Resource, XX Int’l. Grassland Congress, 25 June1 July, 2005, ed. D.A. Mcgilloway. (The Netherlands:
Wageningen Academic Publishers), 265–277.
34. J. V. Stechman, “Fire Hazard Reduction Practices for
Annual-type Grassland,” Rangelands 5(2) (1983).
35. J. McBride, “Plant Succession in the Berkeley Hills,
California,” Madroño 22:3 (1974): 317–329.
36. H. H. Biswell, “Ecology of California Grasslands,”
Journal of Range Management 9 (1956): 19–24.
37. W. H. Russell and J. R. McBride, “Landscape Scale
Vegetation-type Conversion and Fire Hazard in the
San Francisco Bay Area Open Spaces,” Landscape and
Urban Planning 64 (2003): 201–208.
38.Ibid.
39.C. D. Thomsen et al., “Grazing, Mowing and Clover
Plantings Control Yellow Starthistle,” The IPM
Practitioner 18 (1996) 1–4.
40.Ibid.
41.Ibid.
42. J. M. DiTomaso, C. Benefield, and G.B. Kyser,
“Reproductive Biology of Yellow Starthistle
(Centaurea solstitialis): Maximizing Late Season
Control,” eds. M. Kelly, E. Wagner, and P. Warner,
Proceedings, California Exotic Pest Plant Council
Symposium (1998): 4-58.
43. D. R. Cordy, “Centaurea Species and Equine
Nigropallidal Encephalomalacia,” in Effects of
Poisonous Plants on Livestock, eds. R. F. Keeler, K.R.
Van Kampen, and L.F. James (New York: Academic
Press, 1978), 327-336.
44.C. D. Thomsen, et al., “Managing Yellow Starthistle
on Rangeland,” California Agriculture 43(5) (1989):
4–7.
45. J. W. Bartolome, “Valley Grassland,” in Terrestrial
Vegetation of California, 3rd ed., ed. M.G. Barbour, T.
Keeler-Wolf, and A. Schoenherr (Berkeley: University
of California Press, in press).
46.C. D. Thomsen, W.A. Williams, and M.P. Vayssières.
“Yellow Starthistle Management with Grazing,
Mowing, and Competitive Plantings,” Proceedings of
the Cal. Exotic Pest Plant Council Symposium 2, eds.
J.E. Lovich, J. Randall, and M.D. Kelly (1996): 65–68.
47.Morgan Doran, telephone conversations with author,
17, 21, 22 September, and 6 October 2004.
48. Helen R. Sparrow, Helen and Alan E. Launer,
“Report on the 1992 Status of Myrtle’s Silverspot
Butterfly, Speyeria zerene myrtleae, Point Reyes
National Seashore,” Center for Conservation Biology,
Department of Biological Sciences, Stanford, 1992.
62
49. Dennis D. Murphy and Alan E. Launer, “Report
on the 1992 Status of Myrtle’s Silverspot Butterfly,
Speyeria zerene myrtleae, at the Proposed Marin Golf
Ranch site and in Surrounding Areas,” Center for
Conservation Biology, Department of Biological
Sciences, Stanford University, 1992.
50. Grey Hayes. 2000-2001. Unpublished data.
51. L. D. Ford and L.H. Huntsinger. “Draft Report
of Science Advisors: Supplement on Rangeland
Management. Solano County Habitat Conservation
Plan and Natural Community Conservation Plan.”
52.U. S. Fish and Wildlife Service, “Recovery Plan
for the California Red-legged frog (Rana aurora
draytonii),” (Portland: U.S. Fish and Wildlife Service,
2002).
53.East Bay Municipal Utilities District, “East Bay
Watershed Range Resource Management Plan,”
(City: Publisher, 2001).
54. See note 51 above.
55.Ibid.
56. David Lewis, telephone conversation with author, 17
December 2004.
57. F. L. Knopf, “Perspectives on Grazing Nongame Bird
Habitats,” in Rangeland Wildlife, ed. P.R. Krausman
(Denver: Society for Range Management, 1996),
51–58.
58.Mark Homrighausen, telephone conversation with
author, 03 December 2004.
59.C. S. Holling, Adaptive Environmental Assessment and
Management (New York: John Wiley and Sons, 1978);
C. J. Walters, Adaptive Management of Renewable
Resources (New York: Macmillan Publishing
Company, 1986).
60. Ron Paolini, telephone conversation with author, 7
June 2005.
61. H. George and E. Rilla, “Agritourism and Nature
Tourism in California,” University of California
Agriculture and Natural Resources Publication 3484
(2005).
62.Ibid.
63. State of California Code of Regulations, Title 14.
Natural Resources, Division 1.5, Department of
Forestry, Registration of Professional Foresters,
Chapter 10.
64. H. H. Biswell, “Ecology of California Grasslands,”
Journal of Range Management 9 (1956): 19–24; A.
A. Beetle, “Distribution of the Native Grasses of
California,” Hilgardia 17 (1947): 309-357; J. R.
Bentley and M. W. Talbot, “Annual Plant Vegetation
of the California Foothills as Related to Range
Management,” Ecology 29 (1948): 72-79; J. R.
Bentley and M. W. Talbot, “ Efficient Use of Annual
Plants on Cattle Ranges in the California Foothills,”
USDA Circular 870 (1951; L. T. Burcham, California
Range Land: An Historico-ecological Study of the
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Range Resource of California (Sacramento: Division
of Forestry, Dept. of Natural Resources, State of
California, 1957); H. S. Fitch and J. R. Bentley,
“Use of California Annual-plant Forage by Range
Rodents,” Ecology 30 (1949): 306-321; H. F. Heady,
“Changes in a California Annual Plant Community
Induced by Manipulation of Natural Mulch,” Ecology
37 (1956): 798-812; H. F. Heady, “Evaluation and
Measurement of the California Annual Type,” Journal
of Range Management 9 (1956): 25-27; H. F. Heady,
“The Influence of Mulch on Herbage Production in
an Annual Grassland,” Proceedings, 9th International
Grassland Congress 1 (1965): 391-394.
65. See note 32 above; A. R. Dyer, “Burning and Grazing
Management in a California Grassland: Growth,
Mortality, and Recruitment of Nassella Pulchra,”
Restoration Ecology 11 (2003): 291-296; S. Harrison,
B. D. Inouye, and H. D. Safford, “Ecological
Heterogeneity in the Effects of Grazing and Fire on
Grassland Diversity,” Conservation Biology 17 (2003):
837-845; J. T. Marty, K. J. Rice, and S. K. Collinge,
“The Effects of Burning, Grazing and Herbicide
Treatments on Restored and Remnant Populations of
Nassella Pulchra at Beale Air Force Base, California,”
Grasslands 13 (2) (2003): 1, 4-9.
66. Frederic H. Wagner, “Grazers, Past and Present,” in
Grassland Structure and Function: California Annual
Grassland, ed. L.F. Huenneke and H.A. Mooney
(Dordecht: Lower Academic, 1989).
67. H. G. Baker, “Sources of the Naturalized Grasses and
Herbs in California Grasslands” in Grassland Structure
and Function: California Annual Grassland, eds. L. F.
Huenneke and H. A. Mooney (Dordrecht: Kluwer
Academic Publishers, 1989), 29–38; M. A. Blumler,
“Invasion and Transformation of California’s Valley
Grassland, a Mediterranean Analogue Ecosystem,” in
Ecological Relations in Historical Times: Human Impact
and Adaptation, eds. R. A. Butlin R. A. and N. Roberts
(Oxford: Blackwell, 1995) 308–332.
68. L. Huntsinger et al., “Defoliation Response and
growth of Nassella pulchra (A. Hitchc.) Barkworth
from Serpentine and Non-serpentine Populations,”
Madroño 43 (1996) 46-57.
69.California Food and Agricultural Code Division 9,
Part 1, Chapter 6.
70. See note 22 above.
71.Ibid.; see note 20 above.
72. See note 22 above.
73. See note 20 above.
74. Stephanie Larson and James Clawson, “Developing
Livestock Leases for Annual Grasslands,” Cooperative
Extension University of California Division of
Agriculture and Natural Resources, Leaflet 21424
(1987).
75.A. Gordon and A. W. Sampson, “Composition of
Common California Foothill Plants as a Factor
in Range Management,” University of California
Agricultural Experiment Station, Bulletin 627, (1939).
76.Ibid.
77. Steven Winter, telephone conversation with author,
24 October 2005.
78. “Welfare and Veterans’ Organization Exemptions Use
Requirements and Exemption Claim Forms,” [http://
www.boe.ca.gov/proptaxes/welfareorgexemp.htm].
79. “California Constitution Article 16 Public Finance,”
[http://www.leginfo.ca.gov/.const/.article_16].
80. Bill Wiemeyer, telephone conversation with author,
20 November 2005.
81.C.L. Elzinga, et al., Monitoring Plant and Animal
Populations (U.K., Blackwell Scientific, 2001).
82. J. T. Marty, “Effects of Cattle Grazing on Diversity
in Ephemeral Wetlands,” Conservation Biology 19
(2005): 1626-1632.
83. W. E. Frost, J.W. Bartolome and K.R. Churches,
“Disappearance of Residual Dry Matter on Annual
Grassland in the Absence of Grazing,” in XX
International Grassland Congress: Offered Papers, ed. F.
P. O’Mara, et al. (Dublin, 2005).
84. J. W. Bartolome, W.E. Frost, and N.K. McDougald,
Guidelines for Residual Dry Matter (RDM) Management
on Coastal and Foothill Rangelands in California.
(Berkeley: University of California Division of
Agriculture and Natural Resources, in press).
85. W. Clawson, N. McDougald, and D. Duncan,
“Guidelines for Residue Management on Annual
Range,” University of California Division of
Agricultural Science Leaflet 21327 (1982).
86. H. F. Heady, “Changes in a California Annual Plant
Community Induced by Manipulation of Natural
Mulch,” Ecology 37 (1956): 798-812.
87. See note 85 above.
88. J. W. Bartolome et al., “California Guidelines for
Residual Dry Matter (RDM) Management on
Coastal and Foothill Annual Rangelands.” University
of California Division of Agriculture and Natural
Resources, Publication 8092 (2002).
89. W. E. Frost, N. K. McDougald, and W. J. Clawson.
“Residue Mapping and Pasture Use Records for
Monitoring California Annual Rangelands,” UC
Davis Range Science Report 17 (1988); N. R. Harris et
al., 2002. “Long-term Residual Dry Matter Mapping
for Monitoring California Hardwood Rangelands,”
USDA Forest Service PSW-GTR-184 (2002).
90. D. L. Plumpton, “Aspects of Nest Site Selection
and Habitat Use by Burrowing Owls at the Rocky
Mountain Arsenal, Colorado” (master’s thesis, Texas
Tech University, 1992).
91. See note 22 above.
92.Ibid.
93. Bureau of Land Management California State Office,
“Northwestern California Standards for Rangeland
Health and Guidelines for Livestock Grazing
Management,” (1999).
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
63
94. Jeffrey Creque, “Riparian Grazing Management
for Livestock Production and Natural Resource
Protection: An Annotated Bibliography,” Marin
Resource Conservation District (2005).
95. J. D. Robins and J.E. Vollmar, “Livestock Grazing and
Vernal Pools,” in Wildlife and Rare Plant Ecology of
Eastern Merced County’s Vernal Pool Grasslands, ed. J. E.
Vollmar (Berkeley, Vollmar Consulting, 2002).
96. See note 82 above.
97.Ibid.
98. Laurence P. Stromberg, Ph.D., conversation with
author, 22 September 2004.
99. J. W. Bartolome, “Valley Grassland,” in Terrestrial
Vegetation of California, 3rd ed., eds. M.G. Barbour, T.
Keeler-Wolf, and A. Schoenherr (Berkeley: University
of California Press, in press); H. F. Heady, “Valley
Grassland,” in Terrestrial Vegetation of California, 2nd
ed., ed. Barbour M. G. and J. Major (New York: John
Wiley and Sons, 1988). 491-514, 1012-1013.
100. R. D. Jackson and J. W. Bartolome, “A Statetransition Approach to Understanding
Nonequilibrium Plant Community Dynamics in
Californian Grasslands,” Plant Ecology 162 (2002):
49-65; J. W. Bartolome et al, “Response of a Native
Perennial Grass Stand to Disturbance in California’s
Coast Range Grassland,” Restoration Ecology 12
(2004): 279-289.
101. See note 32 above.
102.Ibid.
103. W. Elmore, and B. Kauffman, “Riparian and
Watershed Systems: Degradation and Restoration,”
in: Ecological Implications of Livestock Herbivory in the
West, eds. M. Vavra, et al. (Denver: Society for Range
Management), 212–231.
64
104.Marin County Resource Conservation District, Point
Reyes Bird Observatory, and Natural Resources
Conservation Service, “Recommendations for
Improving Riparian Bird Habitat on Private Lands in
Marin County,” (2001): 1 page handout.
105. Riparian Habitat Joint Venture, “The Riparian Bird
Conservation Plan: A Strategy for Reversing the
Decline of Riparian Associated Birds in California.
Version 2.0,” A Project of California Partners in
Flight and Riparian Habitat Joint Venture. (2004).
106. See note 94 above.
107. R. E. Larsen, et al., “Viewpoint: Livestock Influences
on Riparian Zones and Fish Habitat: Literature
Classification,” Journal of Range Management 51
(1998): 661-664.
108. W. P. Clary and W.C. Leininger, “Stubble Height as
a Tool for Management of Riparian Areas,” Journal of
Range Management 53 (2000): 562-573.
109. B. C. Bellows, Managed Grazing in Riparian Areas.
Fayetteville, AR. ATTRA. National Sustainable
Agriculture Information Service.
110. See note 94 above.
111.C. B. Marlow and T.M. Pogacnik, “Time of Grazing and
Cattle-Induced Damage to Streambanks,” in Riparian
Ecosystems and Their Management: Reconciling Conflicting
Uses, Tech. Coords. R. R. Johnson et al., Proc. First
North American Riparian Conference, USDA FS, Gen.
Tech. Report RM-120. (1985): 279–284.
112. D. F. Lile, et al., “Stubble Height Standards for
Sierra Nevada Meadows Can be Difficult to Meet,”
California Agriculture 57 (2003): 60-64.
113. See note 94 above.
Note: Plant names conform to nomenclature in:
J. C. Hickman, ed., The Jepson Manual: Higher Plants of
California (Berkeley, University of California Press, 1993).
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Glossary
Animal Unit (AU). A1,000-pound cow or its
equivalent in potential forage intake.
Animal Unit Equivalent (AUE). A number
that relates the amount of forage (dry matter
intake) of a specific kind or class of animal
compared to one AU. For example, one mature
sheep consumes about 1/5th of the forage
intake of a 1,000-pound cow, so the AUE for
one sheep is .2.
Animal Unit Day/Month (AUD, AUM). The
potential forage intake of one animal unit for
a period of one day (animal unit day or AUD)
or 30 days (animal unit month or AUM).
Based on 750 pounds of dry matter. One
animal unit day (AUD) equals the amount
of forage required to sustain an animal unit
for one day (about 30 lbs. of forage or about
3% of the body weight of a 1,000-pound cow.
Actual consumption is about 26 pounds per
day plus waste). Forage weights used for this
definition are variable. Some range managers
use 1,000 pounds of forage for one AUM,
which accounts for wasted forage. Others use
a lower rate based on actual consumption (26
pounds per day per AU) and apply a “grazing
efficiency rate” to account for wasted forage.
Available Forage. Forage that is available for
consumption by livestock. Total forage crop
– forage consumed by wildlife – amount to be
retained after grazing (RDM etc.) = available
forage.
Browse/Browsing/Browser. Browse is leaves
and twigs from shrubs and trees consumed
by herbivores. Browsing is the consumption
of browse (as compared to grazing where
herbaceous vegetation is consumed). A
browser is an herbivore whose primary
foraging method is browsing.
Class of Animal. Age, sex, or “stage-of-
production” group within a kind (species) of
animal. Examples include heifer, ewe, or ram.
Cover. Vegetation cover means the amount of
ground surface covered by a plant, as observed
from above the plant. This is usually expressed
in percentages.
Deferment. A period of nongrazing, usually
from the beginning of forage growth within a
year (fall in California) until after seed set (late
spring). A practice sometimes used to enhance
seed production of perennial grasses. “The delay
of grazing to achieve a specific management
objective. A strategy aimed at providing
time for plant reproduction, establishment of
new plants, restoration of plant vigor, or the
accumulation of forage for future use.”
Disturbance (ecological). Any relatively
discrete event in time that disrupts ecosystem,
community, or population structure and
changes resources, availability of substratum, or
the physical environment.
Evapotranspiration. The combination of
evaporation and plant transpiration, which
is the loss of water vapor through leaves and
other plant parts.
Forage. Vegetation that is available and
appropriate for consumption by grazing or
browsing animals.
Forb. A broad-leaved herbaceous plant (not a
graminoid).
Forested Landscapes. Forested landscapes are
legally defined as “tree dominated landscapes
and their associated vegetation types on which
are growing a significant stand of tree species
or which are naturally capable of growing a
significant stand of native trees in perpetuity.”
This has been legally defined as canopy cover
of 10 percent or more of the total rangeland.
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
65
Geomorphological. Pertaining to
geomorphology, which is the science that
treats the general configuration of the earth’s
surface.
Graminoid. A grass or grass-like plant such as
generally expressed as light, moderate, or heavy
etc. These levels of grazing intensity have
been described and illustrated by academic
institutions and public agencies.
a sedge or rush.
Herbaceous. Non-woody plant material.
Grass. Plants in the family Poacea.
Herbivore/Herbivory. An animal that subsists
Grazers. Animals that consume standing
(versus harvested) herbaceous vegetation.
Grazing Period. The length of time that
grazing animals occupy a specific land area.
Grazier. A person who ‘grazes’ livestock,
typically a livestock producer.
Grazing Season. The time period during a year
when grazing is feasible or practical. In lowelevation California the grazing season can be
year-around.
Grazing Systems. The manner in which
grazing and nongrazing periods are arranged
within the maximum feasible grazing season
(in coastal central California, the grazing
season is year around), either within or
between years. Grazing systems often have
descriptive names such as: Continuous or
Yearlong Grazing, Short-duration Grazing,
and Rotational Rest Grazing. Continuous
Grazing is the simplest grazing system and
is very common in low-elevation California.
Short-duration Grazing involves short periods
(days) of grazing alternated with non-grazing
periods that are based upon plant growth
characteristics. Rotational Rest Grazing is a
multi-pasture system in which a full year’s rest
is scheduled among the pastures on a rotating
basis.
Grazing Capacity. The amount of forage (in
AUMs) available for grazing from a unit
of land without causing resource damage.
Carrying capacity can be used synonymously
or it can refer to the capacity of land to
support wildlife and other resources in
addition to livestock.
66
Grazing Intensity. A relative and general term
principally or entirely on plants or plant
materials.
Humus. The more or less stable part of the
organic matter of the soil, so well decomposed
that the original sources cannot be identified
Intermediate Feeders. An animal species that
consumes herbaceous and woody plants and
can adjust their feeding habits to the type of
forage available.
Kind of Animal. An animal species (i.e. Bos
sp.) or species group (i.e. cattle) of livestock or
game.
Meristematic. Pertaining to the meristem,
which is the embryonic tissue of a plant
from which definitive tissues arise by cell
multiplication and differentiation. More
simply, plant growing points.
Overgrazing. Traditional definition:
continued, heavy grazing which exceeds
the recovery capacity of the forage plants
and causes deterioration of grazing lands.
Alternative definition: Grazing during active
growth that is both severe and frequent,
generally resulting in the eventual death of the
plant.
Paddock. A relatively small, fenced enclosure
used to separate livestock. Can also be used to
mean a small pasture that is part of a rotational
grazing scheme, program or system.
Pasture. A grazing area separated from other
areas, usually by fencing; the management unit
for grazing land.
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t
Peak Standing Crop. The stage at which the
year’s forage crop (grassland vegetation) is at
peak maturity and before seeds drop. Forage
production is generally described in units
of weight per unit area (pounds per acre or
kilograms per hectare). The unit of weight
would be measured at peak standing crop, then
dried to determine its dry weight.
Phenology/Phenological. Phenology is the
study of the periodic biological phenomena,
such as flowering, breeding, and migration, in
relation to climatic conditions.
Preference. The selection of certain plants or
plant parts over others by grazing animals.
Range. Rangeland that is grazed by livestock.
Range Condition. Traditional definition: The
present state of vegetation of a range site in
relation to the potential natural (or climax)
plant community for the site based on kinds,
proportion, and amounts of plants present;
suggests current productivity relative to natural
productivity potential. This term is being
phased out. Preferred terms are successional
status and range similarity index. Author’s
note: The concept of “range condition” should
be related to specific management goals for a
given property.
Rangeland. A type of land that includes
grasslands, savannas, and shrublands, exclusive
of cropland, forestland, and urban land.
Residual dry matter (RDM). The old plant
material left standing or on the ground at the
end of the grazing season or beginning of the
new growig season (the fall). Plant material
included in RDM measurements is typically
limited to forage species.
Rest. Leaving an area of grazing land ungrazed
for a specific period of time, such as a season
or a year.
Rhizobia. The plural of Rhizobium, a genus
of bacteria that lives symbiotically with the
roots of certain plants (mostly legumes, in the
family Fabaceae) that fix nitrogen from the
atmosphere.
Rotational Grazing. A general term used for
grazing systems that include two or more
pastures (or paddocks) between which grazing
animals are moved in sequence, thereby
resulting in grazing periods being followed by
nongrazing periods. Rotational Rest grazing
incorporates rotations with planned rest
periods. This is slightly different than simple
rotational grazing as the term rest implies
longer nongrazing periods between the grazing
periods.
Ruminant. Even-toed, hoofed mammals
that chew the cud and have a 4-chambered
stomach, the first one of which is the rumen.
Includes cattle, sheep, goats, bison, buffalo etc.
Compare with cecal-digesting ungulates such
as the horse.
Sensitive Plant Species. Sensitive plant species
are those included on the California Native
Plant Society (CNPS) lists 1 through 3. List
1A includes plant species presumed extinct in
California; List 1B includes rare or endangered
plant species in California and elsewhere; List
2 includes rare or endangered plant species
in California, more common elsewhere; and
List 3 includes plant species that CNPS needs
more information on in order to evaluate their
status.
Stocking Density. Number of animals per unit
area of land at any one point in time. Can be
expressed as AUs/acres.
Stocking Rate. Number of animals per unit
area of land over a specified period of time.
Can be expressed as AUMs/acre. Differs from
Stocking density by incorporation of time.
Reticulo-rumen. The anterior compartment
of the ruminant stomach including the large
rumen and the smaller reticulum.
S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t G R A Z IN G H AN D B OO K
67
Supplemental Feed (also called maintenance
feeding). Harvested forages and concentrates
provided to livestock to meet minimum daily
animal maintenance requirements, thereby
partially or completely replacing grazing of the
standing forage crop.
Thatch. Dead plant biomass accumulated on
the ground surface.
Trampling. The impact to soil and vegetation
caused by animals, especially when congested.
Undergrazing. Continued underuse, thus
often resulting in waste of forage. Can also
be used to indicate an undesirable state for
individual plants or grasslands that accumulate
senescent plant residue or thatch.
68
Ungulate. A hoofed animal, including
ruminants but also horses, tapirs, elephants,
rhinoceroses, and swine.
Unpalatable. Not palatable. Palatability, or the
relish with which animals will consume certain
plant species or plant parts, is determined by
numerous plant characteristics.
Utilization. The proportion of the current
year’s forage production that is consumed or
destroyed by grazing animals. Can refer to a
single species or to the vegetation as a whole.
Expressed as percent utilization. A grazing
plan might call for removing animals after
50% utilization of purple needlegrass.
G R A Z IN G H AN D B OO K S o t o yo m e R es o u rc e Co n s ervat i o n D i s t r i c t